Flock Health and Management

TABLE OF CONTENTS Are Ewe Getting Enough Water Biosecurity Biosecurity Checklist Biosecurity or Biopromiscuity and Keeping the Flock Health Biosecurity Fundamentals for Visitors to Livestock Facilities Management practices for a Healthy Flock Catching and Tipping Sheep Contagious Abortions Sheep Tail Length Digestive System Disorders Disorders of Ewe Reproductive Tract Foot Diseases of Sheep General Information About Abortion Heat Stress Heaven on Earth for Sheep Parasites Hoof Trimming Handbook for the Control of Internal Parasites of Sheep

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Lactation Disorders Metabolic Disorders Associated with Pregnancy and Lambing National On Farm Bio-Security Neurological Disorders Notice to Industry Animal Health Starts on the Farm Nutritional Disorders Common Disorders Affecting Sheep in Ontario Johne’s Disease in Sheep Administration of Medication to Sheep Ontario Sheep Health Program Fact Sheet Maedi-Visna Flock Status Pilot Project Maedi-Visna Factsheet Shepherds Calendar Other Disorders Regular De-Worming Program Regular Vaccination Program Respiratory Disorders Rodent Control in Livestock and Poultry Facilities The Risk to Sheep from Dog Tapeworms Urinary Calculi Sample Flock Health Record Ventilation Basics for Sheep Wasting Diseases

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Yew Poisoning in Sheep Zoonotic Disease

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Are Ewe Getting Enough Water?

By: Jillian Craig Over the summer months it is important to provide freechoice good quality water for sheep. Sheep may drink 40 percent more water during the summer than in winter months.

Water intake can vary depending on animal and environmental conditions and the quality of the water available. Water quality can be affected by different factors such as acidity, toxic elements and compounds as well as algae growth.

Photo By: Lynn Holtrust

Water requirements change depending on the age and condition of sheep, breed differences, stage of production, size, amount of wool covering, body metabolism, feed composition and feed consumption.

Ewes carrying single lambs will have lower water requirements than ewes carrying twins or triplets.

Daily Water Requirements For Sheep Adult Sheep Lactating Ewes Feeder Lambs Baby Lambs

3.8 - 7.6 Litres 7.6 – 11.4 Litres 3.8 – 7.6 Litres 0.4 – 1.1 Litres

(1-2 Gallons) (2-3 Gallons) (1-2 Gallons) (0.1-0.3 Gallon)

In hot temperatures sheep use evaporative cooling and require more water to reduce body temperature.

Sheep that have been shorn have a higher heat load since the wool provided insulation, which is lost. In order to cope in the summer, panting will be increased and under extreme conditions, water consumption may go up as much as 78 percent.

The acidity or alkalinity of the water also plays a role in consumption. If the water has a pH value of 6.5 or lower or has pH value of 8.5 or greater, digestive upsets can occur. If the water is too acidic or basic, the flock may refuse water and reduce feed intake, which can lead to a loss of production. Lime can be added to correct the pH if the water is too acidic. If the water has a pH of 8.5 or above, alum (aluminum sulphate) can be added. Care must be taken however since alum is highly acidic.

Concentrations of elements, which reach toxic levels, can also reduce productivity. Such elements include magnesium, fluorides, iron, arsenic, mercury, lead and selenium. A water analysis could be performed to ensure maximal productivity.

Algae can be another concern for overall water consumption since it can grow in water bowls and troughs. Algae blooms occur when the water contains increased nutrient levels such as fertilizers, or when the water is warm and stagnant.

It is important to ensure that troughs or water bowls are checked daily and cleaned when necessary to reduce disease and algae growth. If using dugouts or ponds the appearance of blue-green algae needs to be monitored since it can be toxic to sheep. In order to maximize production a sufficient supply of good quality, cool, clean water should be available.

Information provided by: Greg Markwick, original source: Industry and Investment NSW and North Dakota State University, www.ag.ndsu.edu

Biosecurity Provided By: Ontario Livestock and Poultry Council (Ontario Sheep News, March 2009) Biosecurity is a term we have come to hear frequently in recent years and can conjure up images of surveillance systems, security fences, complicated sanitizing processes, audits and inspections. However, Biosecurity is really just the protection of livestock and poultry from any type of infectious agent whether viral, bacterial, fungal, or parasitic. People, animals and equipment can spread disease as they move around the farm from one facility to another or can bring diseases with them from off-farm. Some viruses such as Foot and Mouth disease can also be carried in air currents so although most are mechanically spread some are transmitted by other means. Among the many Biosecurity procedures that can prevent these types of disease transmission are some simple measures which have little or no cost associated with them.

There are four stages in the control of disease: preparation, prevention, response or mitigation, and recovery. Biosecurity is part of the prevention stage in the control of disease. However, some of the processes involved in prevention also assist in the containment of a disease, which is part of the response phase. “Biocontainment� is the CFIA term for keeping a know disease on the farm and preventing it from spreading to others.

Another advantage of a good Biosecurity program is that it will also reduce the spread of endemic disease (local diseases) such as Johne’s disease in ruminants as well as foreign animal diseases. And, finally, onfarm Biosecurity practices will also help reduce the spread of potential human pathogens such as Samonella spp., Listeria spp., E. coli O157:H7 and Campylobacter spp.

Listed here are some relatively easy to implement, generic Biosecurity practices for livestock and poultry operations which will reduce the risk of disease entry and transmission on your farm. It is not an exhaustive list by any means but is intended as a starting point. Each small step is an added level of protection against disease and will enhance your disease prevention and Biosecurity risk management system.

There are four primary control areas: visitors (people and vehicles); poultry and livestock; sanitation of equipment and facilities; and, wildlife and pests.

Visitors Visitor control is a critical component. People can spread disease and contaminated material on footwear, hands and clothing. The first line of defense is to reduce the number of external visitors through your facility but also be able to track those who have been to your barns. Knowing who has been there, where they have been and where they are going will be valuable information in the event of a disease outbreak.

This could also help identify the source of infection and possibly determine whether your farm has been infected by an outbreak originating elsewhere.

Below are some practices which will reduce the risk of visitors from bringing pathogens into your operation on their clothes, footwear and hands.

Poultry and Livestock Disease can spread directly amongst birds/animals within your flock/herd and also be introduced by replacements. There are some simple practices which can reduce the opportunity for diseases to be introduced to your operation and control the spread of disease when one occurs.

Equipment and Facilities In general, a clean environment will reduce the risk and spread of disease.

Wildlife and Pests Birds and rodents can carry disease on their feet and fur, and they can destroy thousands of dollars worth of feed, supplies and buildings each year. Even a small population of these rodents may severely contaminate feed supplies. Flies are also a frequent carrier of disease and have been shown to travel up to 1 ½ km from farm to farm.

And, finally, implement a good record keeping system for vaccination dates, footbath changes, disease occurrences, rodent bait changes, etc. This will help you keep track of your Biosecurity practices as well as flag any significant flock/herd heath changes. A little time spent adopting some proactive measures now may save a lot of time and money should you experience a disease outbreak on your farm in the future. Every little bit helps. The old saying, “An ounce of prevention is worth a pound of cure”, aptly applies to biosecurity.

The foregoing article was provided by the Ontario Livestock and Poultry Council. Membership on the Council includes all primary production livestock and poultry groups as well as representation from farm service, feed, processing, veterinary associations and government. The Council provides a forum to facilitate the development and coordination of an Ontario strategy to deal with foreign animal disease and other transmissible livestock and poultry diseases.

Please refer to “Biosecurity Checklist for Livestock Operations” under the Resource Library

Biosecurity Checklist - General Livestock October 2008 Biosecurity is a term we have come to hear frequently in recent years and can conjure up images of surveillance systems, security fences, complicated sanitizing processes, audits and inspections. However, biosecurity is really just the protection of livestock and poultry from any type of infectious agent whether viral, bacterial, fungal, or parasitic. People, animals and equipment can spread disease as they move around the farm from one facility to another or can bring diseases with them from off-farm. Among the many biosecurity procedures that can prevent these types of disease transmission are some simple measures which have little or no cost associated with them.

This document presents a checklist of some relatively easy to implement generic biosecurity practices for livestock operations which will reduce the risk of disease entry and transmission on your farm. It is not an exhaustive list by any means but is intended as a starting point. Each small step is an added level of protection against disease and will enhance your disease prevention and biosecurity risk management system. Your marketing board or association may have more prescriptive measures which you are required to follow.

Post restricted entry signs to keep visitors out of facilities without your permission.

Provide clean routes, not contaminated by manure, for delivery and service vehicles.

Ensure visitors are aware of your biosecurity protocols Set aside a specific parking area for staff and/or visitors and post signage to clearly indicate that is where vehicles should be parked. Ensure the area is well-drained, free of manure or bedding, and a minimum of 15 feet from the barn.

Identify the entrance you wish visitors to use as the access point to your facilities. A homemade sign clearly stating “Visitors’ Entrance� and directional signs if needed will restrict access points.

Locate a drop box away from the barn entrance for feed samples, courier deliveries, bills and receipts.

Provide boots and coveralls for visitors at each barn. If staff are moving between barns, consideration should be given to having separate boots and coveralls for them at each building.

Keep a visitor log book at each barn to record the name and date of visitors and service vehicles. A binder or clipboard with a pen or pencil attached by string is all that is required.

Clean footbaths and a scrub brush at the entry to the barn will help reduce pathogens but must be changed regularly.

Footbaths alone are not an effective means of disinfecting footwear.

Restrict access to facilities to essential visitors only. Keep visitors out of animal pens and feed alleys and do not allow direct contact with animals if not essential.

Ask foreign visitors about diseases in their country of origin and restrict them from your farm if they have been on a farm within the previous 48 hours.

Provide hand washing facilities or a bottle of hand sanitizer for visitors and insist they use it upon entering and exiting from facility.

Provide a container or plastic bag for collecting dirty clothing or disposable items used by visitors.

Wash farm clothing separately from other household laundry and use detergents and bleach or washing soda.

Have separate equipment and tools for handling manure and feed. Mark your forks and shovels with coloured duct tape to identify which is for manure and which is for feed. Avoid sharing manure handling equipment with neighbours.

Wash equipment to be shared with neighbours and insist on clean equipment coming onto your farm.

Establish separate isolation pens for sick livestock, new arrivals and maternity pens. However, sick pens should only be used for sick animals and contact should be restricted between sick pens and maternity or holding pens. Clean all manure from the pens and disinfect after use. Prevent manure movement from the isolation pen to the rest of the herd.

Purchase replacement animals from herds of known disease status.

Establish a herd health program, including vaccination protocols, and review it regularly with your veterinarian.

Vaccinations can prevent some diseases.

Implement a pest control program; wild birds and rodents may carry infectious disease or contaminate feed supplies.

Screen all openings in naturally ventilated barns and exhausts.

Seal off openings into silo roofs.

Screen ledges which could be used as nesting sites.

Clean up feed spills.

Maintain bait stations.

Minimize vegetation and debris around facilities.

Keep pets out of barns and vaccinate them for rabies and diseases common in your area.

Control the fly population by removing manure, using traps, baits or flypaper, using insecticides, or a combination of control measures.

Test water for bacterial contamination.

Ensure feed and water is kept clean; minimize contamination by manure and urine.

Remove dead animals immediately and dispose of them in an approved manner (licensed collector, bury or compost according to protocols, etc.). Clean and disinfect the area after carcass removal and wear protective clothing when handling deadstock.

Remove manure frequently from barns, yards and holding areas to prevent completion of life cycles of parasites and flies.

Store manure so it is inaccessible to livestock, especially young stock.

Assure clean teats and udders for nursing young by providing clean birthing areas and bedding packs with clean straw or shavings.

Minimize disease spread by working with livestock from youngest to oldest and healthy to sick.

For outdoor livestock, prevent animals from having fence-line contact with livestock from other farms.

House young livestock away from older animals were appropriate.

Implement a good record keeping system for vaccination dates, footbath changes, disease occurrences, rodent bait changes, etc. This will help you keep track of your biosecurity practices as well as flag any significant flock/herd health changes.

Our Mission To facilitate the development and coordination of an Ontario strategy to deal with foreign animal disease and other transmissible livestock and poultry diseases.

Biosecurity / Biopromiscuity and Keeping the Flock Healthy By: Paula Menzies, SRVO

What is Biosecurity ?

Biosecurity is an integral part of all procedures we use as veterinarians and producers to promote animal health and protection. Biosecurity involves all measures and policies taken to protect from biological harm, including those undertaken to prevent introduction of disease agents into a specific area (e.g. a farm or region or country) and those that limit the spread or effect of disease agents present in a specific area or group of animals (also known as biocontainment). All measures that promote host immunity or reduce risks from the disease agent or reduce or eliminate environmental factors that increase risk of disease are components of biosecurity.

Most biosecurity measures are applied to the farm or property where the animals reside, but there can be more than one area within a farm (e.g. flocks with different health status), or several properties may be considered to be one unit, e.g. young‐stock on one property and breeding animals on another.

Biosecurity utilizes the principles used in the three pillars of health management: Disease Control‐ i.e. reducing the level of disease to a level where it is not an economic or welfare concern; Disease Eradication – i.e. when a disease agent or the factors necessary for its development are eliminated from a geographic area or population; and Disease Prevention – i.e. when the disease agent or necessary factors are prevented from entering a geographic area or population.

Tools and Protocols Used in Biosecurity There are many tools that can be used to practice biosecurity. For the best results, the use of these tools requires written protocols and possibly training to make sure the producer / employee carries them out correctly. These tools are commonly used to control, eradicate or prevent disease: • Isolation of new arrivals into a farm or region or nation • Isolation of sick animals within a farm or region • Testing for disease prior to introduction to a farm or region • Prophylactic treatment for disease prior to introduction of animals • Vaccination • Test and remove for a specific disease within a herd • Monitoring for disease, e.g. necropsy of on‐farm deaths, diagnostic testing of diseased animals • Prophylactic / metaphylactic treatment of a group of animals at risk of illness • Restrictions on animal movement within a property • Control of animal flow so that naïve healthy animals do not contact high risk animals • Disinfection or other measures to reduce or eliminate infectivity of housing, equipment or feed used in the management of animals • Restrictions of people movement or flow on a property • Protective clothing that can be changed to keep risk of disease transmission low • Restriction of entry of people, vehicles or equipment from outside

To understand how biosecurity can be applied to a sheep farm, it is a good idea to detail the flow of inputs and outputs. Biosecurity Flow Diagram – Sheep Flock shows the inputs as well as the flow of a

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typical meat sheep flock.

Reducing Risk from Introduction of New Genetics: These could be breeding age rams (experienced) or ram lambs (virgin), replacement ewe lambs (bred or open), pregnant, nursing or open ewes. The most common way of introducing a disease to a flock is the purchase of an animal that is already infected with the disease. This can happen in one of three ways: the sheep is incubating disease – appears healthy at the time of introduction and comes down with the disease at some point after purchase; the sheep is recovering from disease – but is shedding the disease agent; and the third way is if the sheep is a persistently infected carrier of the disease agent and is able to shed it in some way. Few people will purchase an animal that is obviously ill, but it is important to educate producers on the risk of buying animals of unknown health status.

Examples of Diseases That May Enter the Flock from Purchased / Borrowed Sheep That Appear Healthy: Lacrimal secretions Pink eye Saliva

Border Disease virus, Foot and Mouth Disease, Rabies Respiratory Tract Respiratory viruses, maedi visna virus, caseous lymphadenitis, enzootic nasal carcinoma Integument

Chorioptic mange, sucking and biting lice, sheep keds, ringworm, caseous lymphadenitis, contagious ecthyma virus (orf) Feet

Dichelobacter nodosus which causes footrot Udder (milk)

MV‐v, Staphylococcus aureus, Johnes disease, Coxiella burnetii Feces

Gastrointestinal / lung parasites + anthelmintic resistance, lungworm,

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cryptosporidia, coccidia, Salmonella, Johnes Disease, Campylobacter abortion, Coxiella burnetii Urine

Leptospirosis, Border Disease virus Reproductive tract Chlamydophila abortion, toxoplasmosis, coxiellosis (Q‐fever), Brucella ovis, scrapie Goats and in some cases llamas and alpacas, share many of these diseases. It is prudent to consider them all as part of the sheep flock – if present.

The risk associated with the source of animals can be evaluated. The following is a suggested ranking of risk – with low risk at the top and increasing risk down the list.

• Washed embryos / semen from approved facility • Fresh semen • Sourced only from flocks of known and low‐risk health status • Single source – unknown health status o Virgin ram lambs and ewe lambs o Mature rams and ewes • Borrowing or lending sheep (rams, 4H lambs) • Multi source / source not closed / or unknown health status of source flock(s) • Sales barns or assembled flocks with no health records

Using AI and Embryo Transfer Exclusively: Semen collected at an accredited AI centre from health tested rams, is a very low risk way to introduce genetics. AI is most often performed by laparoscopic in utero insemination. Fresh semen from untested rams is higher risk for some diseases. Embryos are still considered a risk for scrapie but washed embryos if collected according to the regulations of the International Embryo Transfer Association, are lower risk for most diseases.

Purchasing Sheep from Flocks of Known Low Risk Disease Status: It is very difficult to declare a flock “free” of any specific infectious disease, but through testing and monitoring, it may be possible to declare the flock low risk, based on scientific testing and biosecurity.

Purchasing Sheep from a Single Source: Other ways of reducing the risk of introducing disease is to limit the number of flocks from which animals are purchased. Some flocks are closed and have reasonable health status even if not on a disease status program. Others practice “biopromiscuity” but may have a good name in the industry (e.g. genetics, show performance). Virgin rams and maiden ewe lambs may have a better health status than rams already used in the flock or than ewes that are pregnant. If replacement sheep are sourced only from closed flocks, then the rams have a known health status. Purchasers of rams can put pressure on seed‐stock flocks to enrol in health programs so that the risk that the commercial producers will purchase disease is lowered. However, commercial producers must be willing to pay for superior health status to make sure that it is worth the investment by the seed‐stock producer.

Borrowing or Lending Sheep Some smaller producers may lend (or borrow) rams to add genetic diversity to their flocks. 4H programs are popular with children obtaining lambs from neighbours or dealers to raise and show. Without health matching (farms sharing same health status and biosecurity plans), this practice can lead to health disasters.

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Reducing Risk from New Entrants

Quarantine of New Additions For some diseases, moving a purchased or reclaimed animal back to the farm can be done by first quarantining the animal. The animal should be truly isolated, i.e. housed well away from the main farm, ideally on another property – or at least in housing not used by home sheep. The person caring for the sheep would wear separate coveralls and boots and must practice good hygiene. While in quarantine, the animal can be tested for disease or treated prophylactically – depending on the disease in question.

Unfortunately many of the diseases that we are concerned about, can still be present undetected in the animal – even at the end of a long quarantine period.

Screening New Entries: If the health status of the source flock is unknown, then for some diseases the animals can be screened prior to entry. The screening process will be different for different diseases and some processes are very accurate and others are not. E.g.

• Maedi visna – 2 negative serological tests 8 to 12 weeks apart while the sheep is in isolation – separated from all other animals. This animal will be low risk for introduction of MV. Sheep should be 6 months of age to assure test results reflect infection rather than passive transfer of colostrum.

• Caseous Lymphadenitis (CLA) – palpation of external lymph nodes and a negative serological status. Vaccination may reduce risk although most are only useful if the animals are vaccinated prior to becoming infected. There is still a risk of breaking with disease later or having internal (e.g. pulmonary) abscesses.

• Johne’s disease. Both serology and fecal culture may be negative and the animal may still be infected (poor sensitivity) and because of the long incubation.

• Abortion diseases. Serology may be difficult to interpret unfortunately. The status of the flock of origin is much more important. Virgin animals are of lower risk – particularly rams, but still can be infected (e.g. ewe lambs with chlamydiophila).

Prophylactic Treatment: This is giving a medication to an animal that isn’t sick but may be infected. Some diseases can be eradicated with targeted treatment while the animal is in quarantine. Anthelmintic resistant gastrointestinal parasitism is an example of a disease that can be handled in this manner. Sheep are drenched with combination drenches while in isolation to remove as many parasites as possible. After a few days, the sheep is exposed to pasture with the “farm” parasites in order to dilute any remaining resistant infection that it may still be carrying. Standing sheep in a foot bath with 10% zinc sulphate for 20 minutes and repeat in 5 days while in quarantine is another example of prophylactic treatment to lower the risk of introduction of footrot.

Risk of Disease Transmission from Shows and Sales: Many producers enjoy showing sheep and / or purchasing sheep from sales. Sheep taken to a show can pick up new diseases, although the risk likely varies depending on contact time and disease. Ways to reduce risk include: • Keeping the actual time at the show grounds to a minimum.

• Attend only shows that require health checks prior to unloading animals • If possible, keep the sheep on the truck until its event.

• If not, try to house separately from other exhibitors’ animals. Keep an equipment pen between

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other sheep and theirs.

• Keep feed and water separate.

• Don’t share grooming equipment including stands and clippers.

• Post a sign asking people not to touch the animals.

• Don’t share trucks with other exhibitors unless they know the health status of their flock.

• If a trucker is hired, make sure the truck has been washed out and disinfected prior to using.

Sales animals have the same health status as the worst animal in the group and so the sale will set the tone with respect to biosecurity requirements. Veterinarians and producers always talk about “auction barn” horror stories, where unscrupulous dealers may try to dump their problems. Flocks that are concerned about biosecurity should avoid purchasing animals from these venues.

Reducing Risk from Other Animals Other Livestock on the Farm: For purposes of biosecurity precautions, goats should be treated as sheep as they carry many of the same diseases. Diseases of cattle that can be transmitted to sheep may include: Johne’s disease, choroptic mange, BVD, some contagious mastitis pathogens. Llamas and other camelids can be infected with caseous lymphadenitis as well as gastrointestinal nematode parasites.

Poultry can carry salmonella and campylobacter. Pigs can be a source of salmonella, leptospirosis and listeriosis.

Adjacent Livestock: Livestock that abut the farm can pose a risk, particularly if fence lines are shared.

Q‐fever can be carried on the wind. Mange can be transmitted across fence lines. Breaks in the fence allow opportunities for mixing of animals. Make sure that fences are kept in good condition.

Dogs: Hydatid disease (echinococcus), Cysticercus ovis and C tenuicollis can be transmitted through dog feces. Do not allow dogs to eat fresh dead stock (goats or sheep).

Cats: Cats are the major source of infection from Toxoplasma gondii oocysts and are also an important source of Coxiella burnetii (Q‐fever). While cats are important for control of rodents, cats should be spayed in order to reduce the number of kittens. Toxoplasma oocysts are mostly shed by kittens learning to hunt. Coxiella is mostly shed during parturient events.

Mice, Rats: salmonella, Q‐fever, toxoplasmosis, leptospirosis. Rodent control through use of baits, traps, cats.

Dead‐stock: Dead animals can be a source of environmental contamination or infection of scavenging animals. All dead stock should be promptly removed, buried, or composted.

Manure: Improperly composted manure may serve as contamination of feed (e.g. pastures, hay) or air (e.g. Coxiella burnetii). It should be stored so as to not contaminate water or livestock areas, composted thoroughly, which involves turning and spread on crops (rather than pasture or hay) on still days.

Reducing Risk from Water: Water is usually derived on the farm from wells. Deep wells with good quality water generally pose no risk but shallow wells can be easily contaminated with surface water. Johnes, parasites, salmonella etc can contaminate any surface water source (ponds, streams). Toxoplasma and cryptosporidia transmission can occur from contaminated streams. Wet areas can encourage snail populations and liver fluke; footrot; environmental mastitis. Water troughs should be kept clean and free of manure.

Reducing Risk from Purchased Feeds: Purchased feeds can be a source of toxoplasmosis, mycotoxins, salmonella, listeriosis etc. The producer should only purchase from a reputable dealer and should know the biosecurity on their operation.

Unfortunately it is not possible to be 100% sure that these diseases will not be present in these feeds.

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Reducing Risk from People: The risk from people is not as great as from animals; however this risk varies depending on the disease.

Most purebred sheep producers encourage visits from potential purchasers. As well, feed suppliers, veterinarians, milk truck drivers, salesmen, ultrasound technicians and friendly neighbours can all serve as a source of infection. A few simple procedures can reduce the risk of disease transmission from visitors.

• Have a barrier or gate that prevents direct access from road to barns.

• Include signage at the barrier as well as barn entrance to indicate no entry unless authorized by owner.

• Don’t allow entry if the visitor is wearing soiled clothing (including hats, boots and overcoats) or their own barn clothes. Coveralls can be supplied if that person will have contact with the sheep.

• Provide a footbath with fresh disinfectant solution to scrub footwear or provide disposable plastic boots.

• Have facilities to wash hands with disinfectant soap.

• Don’t allow visitors to handle animals unless wear gloves or have washed hands with disinfectant soap.

• Insist that veterinarians, ultrasound technicians and shearers come with clean equipment, clean coveralls and freshly washed boots. If not, supervise their cleaning before coming into the barnyard.

• Have own shearing equipment and encourage shearers to: visit the farm first in the day; wear cleanly laundering clothing and clean footwear to reduce the risk of transmission of CLA and external parasites.

Reducing Risk from Equipment: Some producers routinely share equipment. Specific diseases can be transmitted, e.g. caseous lymphadenitis on clippers. If equipment is to be shared, it should be effectively washed and disinfected first.

Reducing Risk within the Flock (Biocontainment):

This is just as important in helping to reduce the risk of disease transmission.

• Quarantine sick sheep or new additions away from the rest of the healthy flock. E.g. a sheep being treated for a CLA abscess needs to be housed in an abscess pen that is not used for another purpose (e.g. ram pen, lambing pen). If a sheep aborts, move the pregnant ewes away from aborted ewes since the ground is already contaminated. If lambs are scouring, try to have lambs born into a clean environment.

• Use a sound and strategic vaccination program to control those diseases that have good vaccines, e.g. pulpy kidney, tetanus, abortion vaccines.

• Use prophylactic medications (e.g. anthelmintics, coccidiostats) strategically, including using the appropriate dose and timing.

• Promptly remove dead stock so as not to attract predators and vermin and do not allow other sheep to have access to the dead stock or animal products (e.g. placenta). This can be done by burying or composting where allowed.

• Use a suitable and effective predator control program.

• Manure should be properly composted before being spread onto fields. Don’t allow access to manure piles, including restricting run‐off contamination.

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• • • • • • • • •

Utilize the principles of all‐in all‐out in specific management areas of the farm. This allows disinfection of a premise before introduction of new animals (e.g. diarrhoea outbreak in nursing lambs, do not add newborn lambs to area with sick animals) Reduce risk of disease transmission dam to offspring. For most programs with meat sheep, this will be limited to potential replacement animals. The procedure usually involves: snatch at birth; feed low risk colostrum; feed milk replacer; rear away from disease positive flock.

Control vermin, which can spread disease. This includes preventing access to feed as well as animals.

If cats are to be used to control vermin, make sure are spayed, are vaccinated against rabies and are kept on an effective de‐worming program. Kittens are a risk of toxoplasma transmission.

Providing a kitty litter box may reduce risk of defecating in goat feed.

If dogs are to be used to guard or work with sheep, make sure they are on a tapeworm control program to reduce the risk of cysticercus and hydatid disease. Do not allow dogs to eat dead sheep or goats, including the offal.

Use single use needles and syringes. Dispose of all used needles and syringes in a plastic container (e.g. bleach jug). Disinfect surgical equipment between uses.

Use the principles of animal flow and segregation to prevent exposure of young stock to diseases that adults might transmit. Disinfect when moving animals.

Rams used to breed ewe lambs can be important sources of infection if not also subjected to the same biosecurity checks.

When a disease outbreak occurs, use standard cleaning and disinfection procedures to lower contamination. This includes pens, feeding equipment, handling equipment and protective clothing.

Reducing Risk Through the Use of Good Record Keeping

All sheep must be well identified and records of treatments, vaccinations, movement must be kept up‐ to‐date. Joining flock health programs (e.g. Ontario Sheep Health Program) disease status programs (e.g. Canadian Voluntary Scrapie Certification program, Ontario Maedi Visna Flock Status program) whenever possible, and being a member of the Canadian On‐Farm Food Safety program, will help with the maintenance of good records.

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Management Practices for a Healthy Flock Regularly Monitor your Flock: Check your flock regularly. By paying close attention, the shepherd will become familiar with the normal behaviour of sheep and have a better chance of identifying and quickly dealing with any problems that may arise. Health problems that are caught and dealt with quickly will affect fewer animals and decrease losses in profitability.

Housed sheep should be inspected at least once a day. A convenient time to check your animals is just after feeding. Sick animals are generally less interested in eating and are likely to remain alone as other sheep move to the feeder. Lame animals are also easily detected at this time. When the animals are at the feeder, check for indications of diarrhea (soiled fleece (tag) on the hindquarters). Check the pen floor and walls for anything unusual (blood, diarrhea) and make sure that there is water available. Ewes and lambs should be checked frequently through lambing and lactation. Sheep on pasture should be checked at regular intervals.

In addition to visual health checks, monitoring body condition when you normally handle the animals (e.g. vaccinating, deworming etc.) will help monitor the overall condition of the flock, and pinpoint any sheep that are excessively thin.

Each time you are in the barn or pasture, look for sheep that: • Are not eating or ruminating • Remain separated from the flock • Look ‘depressed’: head down, droopy ears, dull eyes, hunched stance (back arched with forefeet and hindfeet placed close together under the animal) • Look hollow (abdomen/flank is excessively concave and hook bones are prominent) • Show signs of diarrhea (excessive tag or wetness on hindquarters are key signs, excessively watery or bloody diarrhea in the pen) • Show signs of bloat (distension of abdomen, particularly high on the left side where the rumen is located) • Show signs of respiratory distress (laboured breathing, nostrils distended, coughing, copious amounts of nasal discharge) • Show signs of neurological disorders (uncoordinated, moving in circles, abnormal gait or head carriage) • Show signs of lameness or stiffness You may wish to separate and catch animals showing abnormal behaviour for a closer examination.

Taking note of the following characteristics, as well as the animal’s overall appearance, will help you determine what may be wrong. This is also important information to pass along to your vet, if you decide to call for help.

Age (different diseases will be more likely to occur in certain age groups) Gender and reproductive state (e.g. ewes which are very heavily pregnant or that have just lambed) Body temperature (normal for an adult is 100.9-103.8°F; lambs are normally higher than adults) • A high body temperature indicates that the animal is stressed or the body is staging an immune response to an infection.

• A normal body temperature indicates that the problem is due to a non-infectious cause, such as a metabolic disorder • A low body temperature in very young lambs indicates starvation, and in adults may indicate internal bleeding.

Body temperature can be taken by gently inserting a thermometer into the sheep’s rectum. Using a bit of mineral oil or other non-toxic lubricant will make the process easier. Be sure to hold the thermometer while you are taking the temperature, to prevent it from become lost or broken. If you are using a glass thermometer it should remain in the animal for at least 60 to 90 seconds to ensure an accurate result. Digital thermometers signal when the temperature has stabilized (available at pharmacies).

Respiration rate (normal for a sheep is 12-20 respirations/minute) An abnormally high rate is an indication of distress caused by diseases that attack the respiratory tract (such as pneumonia or Maedi-Visna), or could be a sign of severe pain due to injury, etc. It is best to observe respiration rate before disturbing the animal, as the stress of being caught will naturally increase the count. The easiest way to determine the respiration rate is to watch the animal’s abdomen and count each complete breath (i.e. 1 breath=1 inhalation + 1 exhalation). Respiration rate will be high in healthy animals that have been running, are stressed, or exposed to high ambient temperatures.

Heart Rate (normal for a sheep is 70-80/minute). Heart rate will increase under the same circumstances as the respiration rate.

Colour of mucus membranes (tissue around eyes and gums). Pale or bluish membranes indicate internal bleeding or poisoning.

Number of animals affected and pattern of affliction. (e.g. problems such as a lack of water or toxins in feed may acutely (suddenly) affect all animals in the pen, while infectious diseases may affect a small percentage of animals initially, and gradually move through the pen and/or barn.)

Reduce Environmental Stress Stress and the incidence of disease Many of the pathogens (viruses, bacteria, and protozoa) that cause disease in sheep are present in their everyday environment. A normal, healthy sheep that is well fed and given proper housing will generally be resistant to harmful infections by these pathogens. Undue stress, such as poor nutrition and unsanitary or poorly ventilated housing, will greatly reduce this natural resistance. This allows pathogens an opportunity to successfully invade the body. Some management practices you can use to reduce stress are: Maintain a consistent routine Sheep, like most livestock, are creatures of habit and perform best when managed with a consistent daily routine. Sudden changes in routines, surroundings, and feeding patterns will cause stress.

This may lead to a decreased growth rate in lambs and poor reproduction rates in breeding animals, as well as increased susceptibility to disease. Try to have contingency plans in place to deal with sudden changes in temperature, weather or feed supply.

In particular, feeding practices should remain as consistent as possible. Various microbes in the rumen perform most of the feed digestion in sheep. Sudden changes in feed or irregular lengths of time between feedings may disrupt the microbe balance in the rumen and cause potentially fatal metabolic upsets. Changes in feed should be made gradually to avoid digestive disorders such as bloat and acidosis.

For example, if you want to increase lamb growth by feeding a high grain diet, increase the allotment of grain by a small amount each day over a few weeks until you reach the desired level.

Maintaining Facilities to Minimize Stress Proper facilities and housing practices are important for disease prevention. Animals that are overcrowded or not provided adequate shelter will have a greater susceptibility to illness. Be aware that there are provincial regulations in place regarding animal housing and operations, particularly dealing

with manure management and environmental concerns. Building plans and recommendations for housing are available from OMAFRA. General Housing • Adult sheep need less protection from the cold than lambs, and often do well outdoors during the winter if provided with sufficient windbreaks and bedding. An insulated, well ventilated barn or shed is preferable for intensive confinement rearing or lambing in winter • Provide good drainage from buildings and corrals to prevent the build-up of disease-causing organisms, which thrive in poorly drained soil • Provide easy access for manure removal.

• Good ventilation is essential to prevent a build-up of foul air, heat and moisture. Poor ventilation is a leading cause of pneumonia outbreaks.

• Maintain buildings, corrals and fences to prevent injuries to the sheep.

• Have adequate quarantine pens for housing sick or new animals to prevent mixing with the rest of the flock Lambing Facilities • Lambs are born with little protection against the cold. If you are lambing during the winter months, plan to have your ewes lamb in a warm, sheltered facility to prevent neonatal losses.

• Although ventilation must be adequate to prevent pneumonia, ensure there are no drafts directly into pens housing young lambs. Check for drafts and ammonia odours at ‘lamb height’.

• Poor drainage and sanitation of the lambing or mothering pens will lead to the accumulation of disease causing organisms. Provide sufficient bedding and remove manure regularly to keep pens clean and dry.

• Lambing and mothering pens should be draft free but not excessively warm if lambs are going to be moved to colder areas.

• Overcrowding lambs can increase stress and the spread of disease. See the Code of Practice at the end of this binder for recommendations on the space requirements for housing lambs.

Handling Facilities • Good chutes and handling equipment will greatly ease the task of moving and treating sheep.

• Design equipment to minimize stress on sheep and handlers.

• Avoid using dogs that unnecessarily harass or injure sheep.

• Maintain handling facilities to minimize injuries to sheep (fix loose boards, sharp edges etc.).

Water Supply Water is an extremely important part of the diet. Sheep, like all mammals, will die much sooner if denied water than any other nutrient. Check water sources daily. If using automatic waterers, check that the water is flowing and that the bowl is free of contaminants (hay, straw or feces). Feed intake is dramatically affected by water intake. An indication that there is a problem with the water supply is that all of the animals in the pen will go off feed. If the water is unpalatable due to contaminants, sheep may drink enough to stay alive, but production will suffer as feed intake decreases. Lactating ewes require an ample supply of good quality water to ensure a steady milk supply for good lamb growth.

Observe the following practices to ensure a reliable water supply to your flock: • Check and clean waters daily.

• Minimize manure contamination of water by locating waterers at an appropriate height. This will help decrease the transmission of parasites such as coccidiosis, and will improve water intake.

• • •

Have a concrete pad or adequate drainage around watering troughs to prevent foot infections and coccidiosis.

Send a water sample for analysis at least every two years to determine the levels of nitrates, copper sulfate, and total solids.

If ponds are used as a water source, monitor the levels of blue-green algae, as high levels may be fatal.

Feeding Facilities • Use feeders that minimize fecal contamination by preventing sheep from walking on feed.

Fence line feeders, feed racks, and self feeders help control disease and parasite problems by keeping feed off of the ground, as well as reducing feed wastage.

• Set up bunks in a manner that allows for easy cleaning and for easy feeding (avoid having to enter the pens to feed the animals).

• Clean bunks as necessary (i.e. spoiled silage, wet grain etc. may be a health risk) • Allow adequate feeder space so that all animals have equal access to feed. Animals that are not receiving enough feed will be malnourished and more susceptible to disease. Larger lambs that have greater access to feed are more susceptible to clostridial diseases.

Feed Quality and Nutrition • Providing proper nutrition will greatly increase the health of your sheep, through increased disease resistance and prevention of nutritional and digestive upsets.

Manure Management • Proper manure management in sheep housing areas helps prevent the build-up of diseasecausing organisms and keeps sheep clean and dry. Check the air quality at ‘sheep level’ often to ensure ammonia odours are minimal. Some producers remove manure from sheep housing areas regularly. Others prefer to use a manure pack that is cleaned out once or twice through the season. If you are using a manure pack, be sure to add dry bedding as necessary to prevent the surface from becoming damp.

• Store manure away from buildings and corrals to prevent run-off into sheep housing areas, water sources, and feed supplies. Take precautions when spreading manure to prevent contamination of water sources and oversupplying nutrients to soil. Check the provincial regulations regarding manure storage and consider implementing a nutrient management plan on your farm.

Transportation Reduce stress during transportation by: • Loading the truck or trailer appropriately. Sheep tend to push into a corner as a group when panicked, and it is not uncommon to have sheep (particularly lambs) become trapped and die if precautions are not taken during transport. If there are an appropriate number of animals for the space, chances are lessened that lambs will lose their footing and be suffocated. Using separation gates to divide large trailers and avoiding overcrowding will help reduce stress and trampling during transport.

• Thoroughly cleaning vehicles used to transport potential hazardous materials (e.g. farm chemicals, treated seed etc.) before loading sheep.

• Providing sufficient bedding to improve footing and to keep animals clean.

• Clean and disinfecting vehicles after transporting animals.

• •

Avoiding transporting animals in extreme temperatures.

Do not transport ‘downer’ animals or those likely to go down during shipping.

Livestock Biosecurity A ‘Foreign Animal Disease’ (FAD) in your flock can have a devastating effect on the health and welfare of your livestock, and the economic viability of your business.

The same is true for every flock in Canada. We have only to look at the foot and mouth disease experience in the UK to see that an outbreak in Canada would permanently alter your business and cost billions to Canada’s livestock industry.

You can reduce the chance of an outbreak – or the impact, if it occurs – by having your own biosecurity program.

WHAT IS IT? A management program to prevent the spread of disease WHY DO IT? To reduce – in your flock and the national flock: • The chance of introducing disease; • The spread of disease, and; • The cost of disease.

HOW TO DO IT? As part of the management program for your operation. Consider your inputs, the products you produce, the assets you manage (i.e. the livestock, feed, equipment, and buildings), and the costs and risks you are prepared to bear.

WHERE TO GET HELP? From your veterinarian, commodity group, provincial veterinary service, the CFIA, and the Canadian Animal Health Coalition.

WHEN TO DO IT? Now. Implement a control program for your operation right away…and keep it current.

WHO HAS TO DO IT? You. You are responsible for animal health on your operation – that is a critical control point in preventing or controlling the spread of disease to the national flock.

Your program will assist those responding to a major outbreak Do your part…

Prevent foreign animal diseases from entering Canada…

Implement a biosecurity program.

Contact Canadian Animal Health Coalition ‘…promoting a collaborative approach to animal health’ www.animalhealth.ca This bulletin supported by the Western CARD Council

Your Livestock Biosecurity Checklist Visitors Control traffic on and off the farm Post prominent signs to restrict access and provide directions to the farm office.

Discourage unnecessary visitors • All visitors must be accompanied, and prohibited or limited from accessing structures or pens containing animals, medications or feed Keep a ‘visitor log’ • All visitors, service calls and deliveries – no exceptions • Date, name, business, contact information, next farm visit, previous farm visit (see www.animalhealth.ca) Ask visitors to arrive in clean clothes, footwear, and vehicles • On arrival, instruct visitors as to your sanitation practices • Provide clean clothes and footwear if this condition is not met Discuss visitors from other countries with your veterinarian or the CFIA, to assess the risk and appropriate measures Livestock Purchase healthy livestock from reputable suppliers following good management practices and recognized on-farm food safety programs Isolate purchased livestock for a minimum of 2 weeks Purchase quality feed from feed mills that follow good manufacturing practices Separate sick from healthy animals Deadstock should be • Removed immediately from other animals • Disposed of as soon as possible according to provincial regulations • Necropsied to confirm cause of death, if you suspect a contagious and/or reportable disease Sanitation Keep clean…all personnel, buildings, yards, equipment, instruments, feed storage areas, and feed equipment Disinfecting • Choose the right product for the job • Clean items with warm water and detergent, before disinfecting Use disposable equipment once, and discard Wildlife & Pests Control or eliminate vermin Protect your feed and water supplies from fecal contamination by wildlife

Adapted from a Canadian Animal Health Coalition bulletin

Valid Veterinary-Client Relationship Establishing a valid veterinary-client relationship helps ensure that your veterinarian will be familiar with your flock and management practices, in the event that a problem occurs.

A valid patient/client/practitioner relationship exists when: (Source: Canadian Veterinary Medical Association) • The veterinarian has assumed the responsibility for making medical judgments regarding the health of the animals and the need for medical treatment, and the client (owner/caretaker) has agreed to follow the instructions of the veterinarian • There is sufficient knowledge of the animal(s) by the veterinarian to initiate at least a general or preliminary diagnosis of the medical condition of the animal(s) by virtue of an examination of the animal(s) and/or by medically appropriate and timely visits to the premises where the animal(s) are kept • The practising veterinarian is readily available for follow-up in case of adverse reactions or failure of the regimen of therapy.

Catching and Tipping Sheep By: Les Jones; Former OMAFRA Sheep Technician (Modified by OSMA 2010) Catching Sheep At times it is necessary to catch and handle individual animals. If you do not have a handling system and have to catch sheep in a pen, use gates or hurdles to make the pen as small as possible. Do not get into the habit of chasing sheep around a pen. This is not only tiring, but is potentially dangerous for the sheep and the person trying to catch them. Compared to horses or cattle, sheep are not large animals, however, they are very fast on their feet and very strong for their size. Many people have been injured by trying to catch a sheep improperly. Repeatedly chasing your sheep will also make them flighty and difficult to work with.

Manoeuvre the sheep into a corner, extending your arms or using a portable gate to form a visual barrier. Approach the sheep slowly and calmly. The sheep will likely attempt to escape but will probably not move away from the wall, so its moves can be anticipated.

To properly catch a sheep, reach for one of three places.

•

Under the chin: Approach the sheep between its shoulder and flank (if you approach too close to the head, the sheep will likely be able to duck away from you). Cup your hand under the chin and point the nose up to stop the forward motion. Be sure that you get your hand on the bony part of the jaw, not on the throat or you will think you have caught a horse and will be dragged around the pen. Place your other hand on the tail/rump to prevent the sheep from backing away from your hand on its chin.

If you are near a wall, you may wish to gently push the sheep against the wall to prevent sideways movement.

•

Hind leg: Catch the animal by one hind leg, positioning your hand just above the hock. Move your other hand up to control the head as soon as possible. As adult sheep are still able to kick strongly while being held just by the leg, this method generally works best for young, lightweight animals.

•

The Flank: Catch the animal by the front part of the hind leg as near as possible to the body. Place your free hand up to the head as soon as possible. If you control the head the rest of the animal will stay there as well.

Whichever method you use, remember that the wool is not a handle and should not be used as a means of controlling the sheep. This is particularly important when handling animals near slaughter weight, as wool pulling is a significant cause of muscle bruising and meat wastage. To move the sheep lift the tail and let the head down a little, and anticipate that the animal may try to bolt.

Tipping or Turning Sheep Once the animal is caught, you may wish to ‘tip’ the sheep onto its rump to trim feet, inspect the udder etc. Surprisingly, sheep in this position struggle very little and are generally easy to work with (Figure 1). There are a few methods of getting the sheep into this position.

Depending on your preferences, the following method is generally the least tiring and easiest on the handler and the sheep. These instructions are for a right-handed person, if you are left-handed you will likely find it easier if you reverse the directions.

1. Starting position: • Stand the sheep in front of you • Hold the sheep’s head in your left hand, placing your hand under the jaw • Your left knee should be near or just behind the sheep’s left shoulder • Your right leg should be touching the sheep’s side near its left hip • Your right hand on the sheep’s back over the hips 2. Turn the sheep’s nose away from you and right around as if it was trying to reach a spot on its back just behind the shoulder. As soon as you bring the nose around you will feel the weight of the sheep lean against your legs.

3. Put enough pressure on the hips with your right hand that the sheep cannot pick its back feet off the floor. Take a step back with your right leg (your back not the sheep’s!). The hind end of the sheep will start to go down.

4. Continue to bring the head around until the animal is sitting down with its back leaning against your legs.

Steps 2-4 should be done in a smooth motion. The mistake most often made by beginners using this method is to move the wrong foot. Remember to pivot on your left foot and step behind you with the right foot.

Contagious Abortions (Caution: many infectious agents causing abortion in sheep can be transmitted to humans. Pregnant women are advised not to handle lambing ewes) Disorder What do you See? Cause Prevention Enzootic • late pregnancy abortions, stillbirths and weak lambs • the major sources of infection are aborted • a vaccine is available and generally considered to abortion fetuses, placentas, vaginal discharges, and be effective in sheep.

• when first introduced in a flock, abortion rates may (Chlamydia) feces from carriers run from 25-60% of the ewes. After the first • crowding at lambing time increases the risk of outbreak, the incidence of abortion may drop to 1-5% • the organism enters a non-pregnant ewe abortion in the same or subsequent lambing and lays dormant until the ewe conceives season.

• newly purchased ewes and ewe lambs are most (accumulates in the placenta). The susceptible in contaminated farms.

• no effective way to identify infected or carrier organism does not initiate an immune animals. Control measures are, therefore, based • the placenta is often severely damaged and may be response during the dormant stage. During on accurate diagnosis and good hygiene such as retained; membranes are opaque, reddened and thick the infective stage, the ewe develops an isolation of aborting ewes and disinfecting • fetus may have abnormal levels of fluid in the immune response that clears the organism infected pens. abdomen and enlargement of the liver from the system.

• recovered ewes are usually resistant for two to three • ewe usually only aborts once in her years lifetime, but may remain a carrier • an infected ewe may have a normal lamb, but spread the bacteria when stressed Vibriosis • effective vaccine available • late pregnancy abortions, stillbirths, and weak lambs • some infected ewes will continue to shed (Campylobacter, are common. bacteria in their feces.

• clean flocks should be vaccinated if replacement Campylobacter ewes are purchased from other flocks.

• abortion rates may reach 80-90% in previously • new ewes are infected by oral ingestion. jejuni) unexposed flock • replacements should be vaccinated when brought into a flock of vibrio carriers • infected ewes generally recover following abortion • vaccinate just before flushing or breeding or at and can be expected to be immune to re-infection for weaning time. several years • some ewes die of complications such as infected uterus or fetal/placental retentions • new and young ewes are most likely to abort in flocks with a history of vibrio Toxoplasmosis • treatment of ewes during pregnancy with • generally does not cause clinical signs or detrimental • protozoa which causes coccidiosis-like (Toxoplasma anticoccidial drugs and immunization with a live effects in non-pregnant, healthy ewes. disease in cats gondii) vaccine or by exposure of susceptible sheep to • in stressed and immunosuppressed ewes, neurological •infection in sheep follows ingestion of infection before pregnancy signs and death on rare occasions feed or water contaminated with cat feces • the risk of infection greatly reduced by • result in pregnant ewes varies with stage of containing protozoa eggs preventing contamination of sheep feed with cat pregnancy when infected: first two months feces. Keeping cats out of sheep barns to prevent =embryonic death and reabsorption; mid Toxoplasmosis must be weighed against the gestation=abortion or weak lambs; the last trimester benefits of rodent control =weak lambs or healthy, but infected lamb • typical losses averaging 15-20% of the lamp crop.

Contagious Abortions (Caution: many infectious agents causing abortion in sheep can be transmitted to humans. Pregnant women are advised not to handle lambing ewes) What do you See? Cause Disorder Prevention Salmonella • abortion may occur earlier in • ewes that have aborted are • no vaccine available gestation but are most immune but can carry and • ampicillin may help (consult your veterinarian) common in the last month shed bacteria for up to four of gestation. months • abortion rates as high as 70%.

• diarrhea in ewes is common • lambs may also contract the disease and die.

Listeriosis • may also cause neurological • moldy silage most often • never feed moldy silage to sheep, especially pregnant ewes signs as well, although both implicated • no vaccine available neurological and abortions • antibiotics may help, consult your veterinarian are rarely seen at the same time • number of ewes affected depends on feeding practises and degree of silage spoilage Brucellosis (Brucella ovis) • relatively rare cause of • bacteria passed from infected • perform pre-breeding and pre-purchase checks of rams for abortions in ewes rams to ewes unusual scrotal swellings – don’t buy rams with abnormalities • brucellosis is a reportable disease

Digestive System Disorders Disorder Bloat

What do you See? • distension of abdomen, particularly the left side where the rumen is located • depending on severity, the animal may stagger and exhibit signs of pain • can happen as soon as 15 min. after change in diet (i.e. put on pasture for the first time in spring) • in severe cases can be fatal within an hour of first signs • animals of any age can be affected

Grain Overload (Lactic acidosis)

• most often seen in feeder lambs subjected to recent feed changes • depression, stiffness, lack of appetite, blindness, dehydration and diarrhea common • acute cases coma and death • wool loss and lameness may occur if animal recovers

Rectal Prolapse

• most commonly seen in feeder lambs on a high concentrate feedlot ration or lush pastures.

• rectal intestine appears as red ball-shaped structure protruding from the anus.

Cause/Transmission • gas that is normally produced during fermentation and released through belching becomes trapped in rumen • with ’frothy bloat’ (or pasture bloat), the most common type, belching is restricted by the build up of gas in a foam above the rumen contents • ‘free-gas’(or feedlot) bloat occurs when rumen pH drops too low, decreasing rumen motility and preventing release of gas.

• if severe enough the gas build up restricts breathing and causes death • feedlot bloat is most likely to occur on low fibre/high protein diets (i.e. high grain/low forage feeder diets); pasture bloat more common on pastures with high legume content, seldom occurs on pastures that are at least 50% grasses • change in diet occurs too quickly (i.e. taken from a hay diet onto pasture without adaptation time) • if animals are allowed to become hungry between feeding time or pasture rotations, they may bolt large amounts of feed when it is available • sudden intake of easily fermentable feeds (grain, sugar beets, potatoes etc.)

• lowered rumen pH disrupts microbe balance and rumen function • often seen in lambs that are switched onto a high grain diet too quickly

• too close docking affect rectal nerves • excessive straining due to coccidiosis, intestinal worms, constipation, urinary calculi • inadequate feeder space • excessive coughing (dusty feed, poor ventilation, lung worms) • may be a hereditary predisposition

Treatment • severe cases are very serious and should be considered a veterinary emergency Pasture Bloat • immediately remove all other animals from pasture and offer dry hay • forcing bloating animals to walk may be enough to help in mild cases • in more severe cases, use a stomach tube(must go into rumen, not just in the throat) to administer defoaming agent (helps break down gas bubbles and allows animal to belch • trochar or sharp knife: make a hole in the rumen wall ~halfway between the last rib and the hookbone, below the loin- allows gas/froth to escape Feed lot bloat: • stomach tube alone may be effective (allows gas built up due to rumen stasis to escape) • trochar or bloat needle (large needle) also effective in severe cases

• treatment of severe cases is difficult remove grain immediately, feed good quality hay until signs disappear and reintroduce grain slowly.

• antiacids neutralize the lactic acid (treat with bicarbonates) • mineral oil drench will help the ingesta move through the digestive track more quickly • losses can be high as some lambs may die and weight gain is halted while lambs recover • when first seen, replace prolapse and fix with a purse string suture (poor results) • amputate rectum surgically (poor results) • slaughter lamb, especially if close to market weight.

Prevention • make feed changes gradually • be aware of problems with feeding low fibre feeds (fresh alfalfa/grain) • in the spring begin grazing pastures that are at least 50% grass • make sure animals are full when put on pasture for the first time in the spring (decreases intake until rumen can adjust) • avoid turning animals out for the first time if pasture is wet with dew or rain • if many problems with bloat in feeder lambs, consider revising diet to include more high fibre forage.

• consider regular feeding of anti-bloat medication in feed to high risk animals (i.e. feeder lambs) • keep feeding schedules and pasture rotations regular to avoid hungry animals bolting feed • some animals are more prone than others to bloating; consider culling breeding stock that are susceptible • discuss treatment procedures with your vet and know what to do in an emergency • avoid sudden changes in feed • introduce lambs to grain gradually • once lambs are accustomed to grain, maintain regular feeding intervals to avoid lambs becoming hungry and gorging when grain is available again • if feed does run out, allow lambs to fill up on hay before re-filling grain • avoid competition, provide plenty of trough space • good sanitation, feeder and housing • prevention program for worms, pneumonia, and coccidosis • if rectal prolapses occur regularly and other predisposing factors eliminated genetic aspects should be investigated

Digestive System Disorders Disorder Type D Enterotoxemia (Pulpy kidney, Overeating disease)

Type C Enterotoxemia (Acute bloody enteritis) Scours

Coccidiosis

(see Internal parasites for more details)

What do you See? • most often the largest, fastest growing lambs that are affected • can affect any age but most often nursing lambs (2-12wks) and lambs 4-6 months of age soon after entering the feedlot • affected lambs are normally found dead • if still alive lambs may show severe abdominal pain, kicking, head tossing, fever, and perhaps diarrhea • post mortem: kidneys look mushy, sac around heart distended with fluid, may show bloody spots in the intestines • generally lambs under 3 weeks of age • usually found dead • small intestine is discoloured with hemorrhagic spots • affects lambs most often during first 2 weeks of life • lambs born at the end of the season have higher incidence • bright yellow or whitish green diarrhea • lack of appetite, wet hind end, dehydrated (sunken eyes, gaunt) • many lambs that are receiving ample milk will have some yellowish scours, however, they remain bright and alert • common intestinal infection characterized by thin, watery diarrhea, often bloody • most often seen in feeder lambs, 23weeks after entering feedlot

Cause/Transmission • bacterium (Clostridium perfringens Type D) normally present in the intestine can multiply rapidly under certain circumstances and release a toxin • toxin causes systemic blood poisoning

Treatment • usually too late • if a nursing lamb dies, remove rest of flock from lush pasture and/or reduce creep feed • if a feeder lambs dies: decrease level of grain in diet and avoid letting lambs become hungry between feedings

Prevention • vaccinate against Clostridial diseases • see page 135 for vaccination schedule • introduce increases in grain slowly

• bacterium (Clostridium perfringens Type C) in intestine produces toxin causing systemic poisoning

• as with Type D, usually too late

• vaccinate ewes against Clostridial diseases ~ 1 month before lambing

• overcrowding, cold/wet lambing facilities, poor nutrition (stress leading to a weakened immune system) • indigestible milk replacer • lack of colostrum • lambs from ewe lambs may be more susceptible (decreased immunity in colostrum)

• if problem is wide spread in flock discuss with a veterinarian to determine best antibacterial medication to administer • change milk replacers if that may be the problem

• good pre-lambing nutrition for the ewes and 7 or 8-way vaccination (increase antibodies to colostrum) • good management, sanitation, dry bedding, avoid overcrowding • isolation of affected ewes and lambs • make sure lambs get colostrum within two hours of birth

• caused by an intestinal protozoa (coccidia) • sudden changes in diet and stress can cause coccidia to rapidly multiply, causing infection

• consult with a veterinarian, • anti-coccidial medication can be obtained from a vet • water and electrolyte treatment for severely dehydrated lambs

• good feeding management (place feeders and waterers to avoid fecal contamination) • provide prescribed daily levels of an coccidiostat in ration (rumensin, decox) This type of medication requires a vet prescription for lambs

Disorders of Ewe Reproductive Tract Disorder Vaginal Prolapse

What do you See? • seen in ewes and ewe lambs in the later stages of pregnancy.

• mild vaginal prolapses are difficult to detect. Sometimes if the ewe is lying down a small round protrusion of the vaginal wall from the vulva will be seen. As the problem progresses, more of the vaginal wall can be seen.

• drying, infection, irritation and freezing of the tissues lead to the ewe straining.

If the prolapse is large enough the urethra may become blocked and the ewe will be unable to urinate.

• in very severe cases, the vaginal wall will tear, the intestines may be pushed out, and the ewe will die quickly.

Cause over-conditioned ewes too much coarse roughage genetic predisposition overcrowding at feeders hypocalcaemia, calcium phosphorous (Ca:P) imbalance in diet) • excessive coughing or straining • age: three year old and older ewes more susceptible • internal pressure and lack of room, e.g., full rumen, multiple lamb pregnancy • • • • •

Uterine Prolapse

• occurs directly after lambing • uterus becomes inverted and hangs from the vagina as a large red mass with the cotyledons or “buttons” readily identifiable.

• if the ewe appears very weak, has pale mucus membranes, and feels cold, she is most likely haemorrhaging internally and little can be done to save her.

• excessive straining from difficult births is often the cause • genetic predisposition?

Malignant Edema

• hot, puffy, painful swelling in the region of vulva (greenish discoloration) • ewe depressed, off feed, quite ill, could be quite lame on one side in early stages • death usually follows in 24 hours. .

• a deadly clostridial disease (bacteria Clostridium septicum and C.chauxei) commonly seen at lambing time • failure to properly wash your hands before assisting a lambing ewe • unsanitary lambing facilities • bruising, laceration of vagina during lambing • infected afterbirth membranes

Treatment • needs immediate attention • clean prolapsed tissue gently with a mild disinfect and replace.

• If found in early stages the prolapse may be replaced quite easily • more difficult or almost impossible if found caked with manure, sunburned or frozen • there are products on the market that can be used to hold it in position, for example, plastic spoon-shaped retainers and trusses.

• a veterinarian should be consulted before attempting suturing of tissue • uterine prolapse is an emergency - call your veterinarian immediately.

• an epidural anesthetic will be given to prevent straining and the prolapse gently washed and replaced. The vulva will be sutured closed to prevent a recurrence.

• none

Prevention • provide adequate feeder space to prevent ewes from pushing and shoving for grain.

• provide a high quality of roughage during the last trimester of pregnancy to ensure adequate vitamin and mineral intake, especially calcium.

• cull affected ewes (although the problem will correct itself after lambing, it will probably occur with future pregnancies) • don’t use offspring from such ewes as replacement breeding stock

• do not dock tails too short • if the water bag breaks, but there is no further progress within an hour, the ewe should be examined, and if possible the problem corrected before the ewe becomes exhausted • get competent help for difficult lambing cases • ensure adequate rations during the last stage of pregnancy • prevent ewes from becoming obese • Clostridial vaccination • wash hand and clean vulva using soap and warm water before attempting to help the ewe during lambing

Foot Diseases of Sheep Disorder Foot Rot

What do you See? • starts as a scald with moist, reddened skin between the claws of the hoof • as the infection progresses, it spreads and the outer portion of the hoof wall (‘horn) which, starting at the heel, will separate away • dead tissue appears as a greyish, moist zone beneath the loose horn • there is often a foul odour, but no pus formation • maggot infestation is a common complication during the fly season • acute lameness, sheep walk on their knees if front feet are infected • sheep lose body condition because of pain and some interference with feeding • no abscesses form, and the area above the hoof is seldom involved • sheep may not be obviously affected but they could be carriers.

Cause/Transmission • both Fusiformis necrophorus and Bacteroides nodosus types of bacteria need to be present to cause foot rot • initial scald is caused by f.necrophorous bacteria; scald irritation allows b.nodosus bacteria to enter deeper layers; infection created by b.nodosus allows deeper invasion of f.necrophorous • bacteria is picked up from the soil and certain conditions increase likelihood of infection • in wet footing (heavy rainfall, marshy pastures) hooves become soft and surrounding skin is easily irritated or injured • bacteria grow in the absence of oxygen, therefore overgrown or deformed hooves are more susceptible as there tend to be cracks and pockets in hooves

Foot Scald

• inflammation of skin between the toes • some separation of the hoof from the foot may occur, but there is no greyish rotting and no offensive odour

• caused when Fusiformis necrophorus alone is present • seen when feet are wet for a prolonged period (heavy rains, marshy pastures)

Foot Abscess

• may separate hoof from sole • often causes swelling and rupture of skin above the hoof • trimming shows yellowish pus material when abscess is opened • sheep may become quite ill and die of blood poisoning in acute, severe cases • if chronic infection is deep enough to involve joints and connective tissues, simple treatment will not be effective and chronic arthritis may develop

• infection entry is through broken toes, scald injury, cracked walls, injury on junky yards, wooden sticks

Treatment • foot rot is notoriously difficult to completely clear up - contact your veterinarian for an exact diagnosis and detailed recommendations for treatment.

• treatment is expensive, labour intensive, and may take weeks to months to be successful • footbath is essential (formaldehyde, copper or zinc sulfate) • examine and trim feet of all sheep (even those not showing signs disinfect trimmers between each sheep) • identify all affected sheep and isolate as a ‘diseased’ flock • new cases will likely occur, so monitor ‘clean’ flock closely and remove affected animals as soon as possible • ‘clean’ and infected animals should go through footbath (individual sheep must stand for at least five minutes) • your vet can provide a detailed treatment regime • as infection remains on the surface, treatment less intensive than with foot rot • put sheep on clean dry ground and they recover quickly • foot bath may speed recovery.

• simple abscesses may be drained, flushed out with 2 per cent tincture of iodine and an injection of antibiotic given into the muscle • sheep with badly swollen foot may need to be treated by a veterinarian

Prevention • only buy new stock from known and reputable flocks • check feet on new stock for any signs of rot, and keep in quarantine for 23 weeks before mixing with the rest of the flock • perform regular hoof trimming on the entire flock and/or cull sheep with poor feet • avoid wet, muddy pastures and corrals if possible

• avoid using wet pastures and corrals

• maintain pastures (clear junk etc)

General Information About Abortion Cause • most abortion diseases are spread by direct contact through feed and water or contaminated material (fluids, placenta, fetus). Brucellosis, an exception to the rule, is spread by the ram during breeding.

• diagnosis (determining the type of organism causing the abortion) is difficult by looking at fetus It is important that the whole fetus, its membranes (placenta or afterbirth) be submitted to the provincial veterinary lab in all cases of abortion. Fresh, preferably clean specimens are necessary for good results

If the laboratory cannot detect, isolate or identify infectious abortive agents after a number of suitable submissions, one should look for non-infectious causes of abortions such as: • nutritional deficiencies (vitamin A, iodine) or malnutrition • rough handling, accidents • exhaustion after stress, transport over long distance, dog attacks, etc.

• any disease accompanied by high fever • hormonal disturbances, (estrogens, or progesterones).

• young ewes that are still growing may be more prone to stress/nutrition related abortions

Prevention • abortion storms can rapidly decimate your lamb crop and profits for an entire year. It is therefore very important to implement preventative measures and minimizing the spread of the disease if it does occur.

Prevention:

• consult your veterinarian about implementing an effective vaccination program (possibly including the use of a coccidiostat) • do not feed on the ground and provide clean water.

• prevent contamination of feed and water with feces of rodents, birds and cats. Neuter cats and maintain a stable adult cat population.

• maintain first lambing ewes as a separate unit.

• maintain purchased replacement ewes as a separate unit.

• avoid stressing the sheep. Avoid crowding and unsanitary facilities.

• do not bed pregnant ewes with bedding from lambing area.

• maintain high standards of sanitation and hygiene while lambing; wash and disinfect hands frequently.

If abortions do occur: • submit aborted fetuses and placentas to a diagnostic laboratory to identify the infectious agents. If the abortion storm is prolonged, several samples should be submitted as there may be more than one cause.

• immediately isolate aborted ewes from the rest of the flock – do not mix with replacement stock • clean the area where the ewe aborted-remove all traces of fetal material (bury) and spray area with disinfectant • consult with your veterinarian about possible antibiotic or antiprotozoal medications • check for contamination of feed supplies (especially if you are using silage).

• monitor and possibly treat aborted ewes for uterine infections (injectable antibiotics and/or uterine infusion)

Heat Stress By: Jillian Craig In the hot summer month’s sheep may be susceptible to heat stress. Heat stress can weaken the immune system, reduce productivity, lower birth weights and semen quality may be reduced. With a few simple management strategies it is easy to eliminate this issue from the flock. By providing shade and cool, clean water sheep should not suffer from heat exhaustion or stress. Newly shorn sheep should have access to shelter Photo By: Debra Garner to reduce the risk of sunburn. On extremely hot days the flock may have a reduced feed intake so it is important to provide good quality feed.

Providing a barn or trees for the flock to rest during the hottest part of the day will maximize production and prevent losses.

Information provided by: Industry and Investment NSW, http://new.dpi.vic.gov.au/

Heaven on Earth for Sheep Parasites!

By: Paula Menzies, Department of Population Medicine, University of Guelph and Andrew Peregrine, Department of Pathobiology, Ontario Veterinary College (Ontario Sheep News, September / October 2006) The hot, wet summer is excellent for growing crops and pastures, but for Ontario sheep in may be a growing threat. Because of the warm, humid temperatures common to the summer months, losses due to gastrointestinal nematode parasites (GIN) are on the rise.

The two species of GIN that cause the most havoc are Haemonchus and Ostertagia.

Haemonchus will suck blood from the animal, while Ostertagia sucks proteinaceous fluid.

Sheep become infected with Haemonchus by something they do everyday- eat! The adult form of the Haemonchus worm takes residence in the animal’s glandular stomach, laying eggs that are passes externally through the feces. Once outside the animal, the eggs hatch and mature to infective larvae within approximately 7-14 days, depending on the weather. Infective larvae are then eaten by sheep out on pasture and the whole cycle- which takes about 21 to 28 daysbegins again.

The heat of the summer days hastens the hatching and maturation of the larvae. And the moisture in the air helps release the larvae from the fecal ball- as well as assists in placing the larvae higher on the grass stem (making it easier for the sheep to ingest).

The most risky pastures to sheep are those covered by dew on a nice sunny day. Warm and moist conditions help the larvae live for months so with the recent humid weather, larval contamination on pastures is sky rocketing.

Signs of parasitism include poor growth, diarrhea, bottle jaw (edema under the jaw), weakness, lethargy, and pale mucous membranes due to blood loss. In serious cases of Haemonchus, sheep may drop dead on pasture without any signs due to the severe and rapid loss of blood experienced by the animal.

A single Haemonchus (H. contortus) worm will suck about 0.05 ml of blood per day, which may not sound like much until you calculate that a moderate load of 1,000 worms will suck about 50 ml of blood per day. A 70 lb lamb has a total blood volume of approximately 2.8 litres. In one week alone, 1,000 parasites will drain that lamb of over 12% of its total blood volume. It is not unusual to see lambs that have lost well over 50% of their blood volume with these infections. Combine these losses with the loss of blood plasma and protein and we have a severely compromised or possibly dead lamb.

Most producers usually de-worm their flock at pasture, putting a stop to the infection before major losses occur. But this year, submissions to the Animal Health Laboratory at the University of Guelph have been revealing an unsettling trend. Late July to August is the traditional time when pathologists have dead lambs (and adults) submitted with very high loads of parasites in the gastrointestinal tract (particularly Haemonchus). But what pathologists have been noticing this year is that submitted animals have been recently de-wormed within a few weeks of being examined. This could mean one of two things: either the de-wormer was not administered correctly to the sheep, or the parasites are resistant to the de-wormer.

If it is a case of incorrect administration that can be equally solved. All producers are encouraged to become knowledgeable with administration techniques.

When administering a de-wormer to a sheep, it is critical that the following be done to prevent under dosing:

• • • •

Estimate the weight of the sheep correctly. It may be necessary to weigh a few of the animals.

Based on the above information, dose not for the average weight but the heavier weight of the sheep being treated.

Make sure the dose gun is correctly calibrated, i.e. it is delivering the amount of dewormer that you think it is.

When administering the de-wormer, make sure that the sheep gets all of it. A little drizzle out the side of the mouth could make the difference between an effective or ineffective treatment. Make sure the drench gun is placed over the back of the tongue; steady the sheep’s head so all of it gets swallowed.

Some other issues to note: • In Canada right now, Ivomec (Merial) is the only licensed anthelmintic 9de-wormer) available either as a drench or an injectable. Make sure that you do not use another form of Ivomec (e.g. our-on for cattle) as it is not well absorbed and so leads to under dosing.

• Don’t use pour-ons at all on sheep. There is scientific evidence that absorption of the drug is inadequate, even in shorn sheep.

• There are other commercial products on the market that are not licensed for sheep but are effective. Talk to your veterinarian before using these products to make sure they are right for your situation.

• Many “alternative” de-wormers are available, often with little proof that they work- and sometimes with proof that they actually don’t work. If you wish to use one of these products, make sure that you monitor your sheep closely so they don’t become diseased or die.

If it is not a case of incorrect administration, but rather a case of resistance, that is a whole other bag of worms. Anthelmintic resistance (AR) in sheep has been reported around the world, particularly in hotter climates such as Australia, South Africa, and the USA- but is has not yet been reported in Canada. While some parasite eggs and larvae can live out the winter under the snow cover, Haemonchus doesn’t seem to be able to. The parasite can only survive winters if it stays alive in the gastrointestinal tract of sheep. So Canadian winters give us a natural “cleansing” season for our pastures and may have helped protect us from AR. However, with the fluctuations in weather patterns, this natural “cleansing” season may not be as effective as it once was.

With this in mind, farmers may be concerned about resistance levels in their flocks.

Producers can contact their vets who can perform tests to determine if their flock is AR. The name of the procedure used by vets around the world is the Fecal Egg Count Reduction test (FECRT). One way of determining worm burden in sheep, is to count the eggs in the feces.

However, this is not the best method as egg counts can vary quite a bit from day to day and depend on other factors such as diet and activity. But by counting the eggs quantitatively (eggs per gram (epg) of feces) in several animals, vets can get a good idea of the parasite burden in the group of animals. If you suspect AR in your flock (sheep not responding to treatment or losses within a few weeks of treatment), contact your vet to set-up a FECRT. If AR is confirmed within a flock, producers along with their vets need to work as a team to control it. There are many strategies that can be completed in such a case and they do not all involve using a different de-wormer.

At the University of Guelph, researchers are looking at the natural epidemiology of GIN in Ontario and Quebec flocks with a plan to use these finding to propose strategic control measures more suitable for the Canadian climate.

Please contact the extension veterinarians at OMAFRA for further information (Wellington Place, R.R. #1, Fergus, ON N1M 2W3, Phone: (519) 846-0941, Fax: (519) 846-8178).

Hoof Trimming By: Dr. Cathy Gallivan, PhD: ‘Sheep Canada’ Summer 2002 (Modified by OSMA, 2010) Sooner or later most shepherds have to trim a few feet. The frequency of this job varies with the breed of sheep and the environment in which they are kept. In an extensive grazing environment, where sheep are required to walk long distances, hooves wear down naturally and generally require little trimming. Sheep housed in smaller areas or in pastures with soft, wet ground may require trimming at least once or twice a year. Sheep that are housed on manure packs, for instance, may require more hoof care.

The rate of hoof growth varies to some extent with the breed. Some breeds, such as Rambouillet, have been selected for their ability to travel long distances in very extensive grazing conditions. These breeds have feet that grow faster than other breeds commonly found in farm flocks grazing smaller areas, and may require more trimming. The other major difference between breeds is the hardness of their feet. Sheep with white feet generally have hooves that are softer and easier to trim than breeds with black feet. This is another example of breeds being adapted for a particular environment, as many of the breeds with black feet (such as the Suffolk or Hampshire) originated in parts of the UK where the ground may be soft and wet.

Regardless of colour, sheep feet are softer and easier to trim when the sheep have been standing on soft or wet ground (e.g. late spring) than they will be after standing on hard dry ground (e.g. mid-summer).

Shepherds planning to trim the whole flock in one session would be well-advised to plan the event to coincide with a period when the feet will be softer and easier to trim.

In some flocks, foot trimming is done at least once a year on all animals, often before they are turned out onto summer pasture. However, a recent survey of sheep producers in Alberta revealed that many flock owners simply monitor the hoof condition of their sheep and trim individual animals as required.

There are a number of foot trimming tools available that are specifically designed for trimming sheep.

The type of design you choose is a matter of personnel preference. Some have handles that roll back and forth to make it easier on the operators hands. Some have serrated blades and some blades are plain. Lighterweight pruning shears are cheaper and may be suitable for small flocks, but won’t stand up to trimming hundreds of animal’s feet.

The typical method involves catching, tipping, trimming all four feet and then releasing the sheep. Every shepherd will develop his or her own style of hoof trimming. The diagram below will get you started. Be careful and don’t get frustrated. You’ll get faster as you gain experience. If you make a mistake and cut too deep, don’t panic. It’s a bit like getting a hangnail – it does hurt and it may bleed, but no one ever died of a hangnail.

As sheep have gotten bigger and stronger and shepherds older and smarter, a number of operations have turned to tipping tables or crates. Crates are usually placed in the handling system so that a sheep walks down the chute, into the crate, and can then be easily turned on her back for trimming. These crates can considerably speed up the job of foot trimming, and make it so that the shepherd can walk upright when the job is done! Some models require turning the sheep (in the crate) by hand, while others are spring loaded or hydraulically operated. When there are a lot of sheep to be trimmed, feet are particularly hard and dry, or when the use of a tipping table makes it important that the animals be handled quickly, pneumatic hoof trimmers that run off air compressors can also be used to dramatically reduce the time required.

For more information regarding the magazine ‘Sheep Canada’ call the toll-free number 1-888-241-5124 or check out their web site www.sheepcanada.com

Trimming Hooves:

Team Members Andrew Peregrine, Silvina Fernandez - Dept Pathobiology, University of Guelph David Kelton, Andria Jones, Paula Menzies, America Mederos (PhD candidate), Alessia Guthrie (MSc candidate) - Dept Population Medicine, University of Guelph Ralph Martin - Organic Agriculture Centre of Canada, Nova Scotia Agriculture College John VanLeeuwen - Dept. Health Management, University of Prince Edward Island Ann LeBoeuf, Francoise Corriveau - Centre d'expertise en production ovine du QuĂŠbec Jocelyn Jansen - Veterinary Services, Ontario Ministry of Agriculture, Food and Rural Affairs Contact Person: Dr. Paula Menzies, Dept. Population Medicine Ontario Veterinary College, University of Guelph Guelph, ON N1G 2W1 - (519) 824-4120 ext 54043 pmenzies@ovc.uoguelph.ca

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Lactation Disorders Disorder Mastitis

• • • • • • •

BlueBag Masitis

• • • • •

Agalactia (Lack of Milk)

• • • •

• • •

What do you See? mastitis can develop rapidly may be an obvious cause (damage to udder, bruising, wire cuts, sore mouth scabs) various levels of severity (some cases are sub-clinical, but will still cause injury to the udder and decrease milk production) in the obvious cases, the udder becomes hot and painful (may cause fever) ewe carries one leg away from udder lamb may look hollow if milk decreased mastitis is a common sign of the Maedi-Visna virus, both sides of the udder are hard but not hot very severe form of mastitis udder is very swollen, hard, and has a greenish colouration infection generally spreads through the body (systemic poisoning) the ewe becomes feverish, quite ill and may die in a day or two if ewe recovers, the affected half of the entire udder no longer produces milk ewe produce little or no milk. may be little udder development as the ewe nears lambing no fever, illness, pain, or edema of udder there may be a hard fibrotic lump within the parenchyma of the udder with an extension from this fibrous mass descending down into the teat canal, causing an interruption of milk flow milk (if there is any) appears normal in colour and consistency, simply not enough of it occurs among first time lambing ewe lambs as well as older ewes. maternal behaviour may be normal, or ewes may be less willing to allow lambs to nurse (especially with young ewes)

Cause • bacteria such as Staphylococcus spp. or Pasteurella spp causes infection of the udder • maybe related to injury or unsanitary conditions

Treatment • depends of severity of infection • frequent stripping of milk out of udder (at least twice per day) • intravenous or intramuscular antibiotics injections may be useful

Prevention • unless lumps and abscesses are very small, the affected and recovered ewe should be culled from breeding flock.

• keep ewe housing areas clean and well bedded • if you suspect MaediVisna, see Respiratory Disorders for details

• as above, likely to have an udder injury

• call your vet • hot packs applied to udder using hot water and liniments • intravenous or intramuscular antibiotic injections may be useful • early treatment is essential

• as above

• • • • • • •

• none (some ewes are slow to start milking after lambing, and milk production may pick up after a few days)

• cull affected ewes.

cause not known possible influencing factors: chilling of udders excessive barley feeding mastitis infection not cured mycoplasma infection early lambing (Dec-Jan).

Metabolic Disorders Associated with Pregnancy and Lambing Disorder Pregnancy Toxemia

Hypocalcaemia (Milk Fever)

What do you See? • usually affects ewes carrying multiple lambs in late pregnancy • ewes who are too fat or too thin are more at risk • usually occurs in more than one ewe in the flock, as the flock is exposed to the same feeding conditions.

• ewe keeps separate from the flock, and appear depressed (head down, droopy ears), eventually progresses to weakness, staggering and blindness.

• total lack of appetite, normal body temperatures 38.9ºC (102º F) • grinding of teeth as though in pain, staggering, loud breathing • sometimes there are convulsions, coma and death.

• breath smells ‘sweet’ • a post mortem exam shows fatty liver and multiple fetuses in late development • only silage, hay, and straw are being fed (energy shortage).

• usually occurs shortly before or after lambing • staggering, tremors and a stilted gait.

• sheep may go down after an hour or two • hind legs stretched backwards, head may be turned toward the flank • although another name for this disease is milk fever, there is no fever, temperature is usually decreased to 35.0 to 36.7º C (97-98º F) • ewes often look bloated (rumen motility decreases and gases accumulate) • most ewes will die if not treated promptly.

Cause • ewe is unable to consume enough energy to support her and her rapidly growing lambs because of inadequate nutrition or loss of appetite.

• reduced feed intake capacity due to growing fetuses in late pregnancy (digestive fill is resticted0 • improper sugar metabolism, which leads to low blood sugar, high ketone levels in blood, fatty liver.

Treatment • call your vet • generally unsatisfactory • glucose intravenous gives only temporary results, and is not very effective • glycerol or propylene glycol by mouth four times per day • consult with your veterinarian about inducing lambing or performing a Caesarean section.

Prevention • adequate and increasing energy levels must be provided in the diet during the last 4 to 6 weeks of gestation • provide the pregnant ewes with fresh water and adequate feeder space.

• regular body condition scoring will aid in early detection and prevention of this disease.

• keep ewes in good condition, not too fat, nor too thin • increase grain intake gradually over final six weeks of pregnancy, by ~1.5lb per head (grain provides increased energy, while causing little gut fill) • avoid stress, such as excessive handling, shipping, deworming, vaccinations, overcrowding, feed changes during final four weeks of pregnancy.

• pregnant or lactating ewes having low levels of blood calcium due to the growth of the fetus or the increased milk demands.

• high Ca and low P in feed, e.g., lots of good alfalfa but no grains or minerals causes body to release Ca from body stores too slowly for the sudden Ca demands due to lactation • excessive handling, shearing, feeding stresses, deprivation of feed may cause this disorder

• an injection of 80 ml of calcium borogluconate under the skin will help most ewes within an hour.

• severe cases may require an intravenous injection

• avoid rough handling during late pregnancy (avoid stress) • good quality Ca-P minerals should be available at all times.

Watch copper levels if fed free choice.

• avoid sudden changes in feed or interruption in feeding routine with pregnant ewes.

Neurological Disorders Disorder Tetanus (Lockjaw)

What Do you See? • limb stiffness, stilted gait • as disease advances, animal will stiffen completely and not be able to open jaw • convulsions, often triggered by sudden noises • 3rd eyelid membrane may be visible • breathing difficult • death occurs in 3-4 days

Treatment • usually too late by the time animal shows obvious signs • clean damaged area and any dead material • if animal has not been previously vaccinated, dose with tetanus antitoxin and tetanus toxoid (vaccine)

Prevention • vaccinate ewes using an 8-way (Clostridial and tetanus toxoid) prior to lambing • use clean equipment for castration and docking, house lambs in sanitary conditions • don’t use elastrator bands on farms with previous cases of tetanus

Listeriosis (Circling Disease) (also see abortion diseases)

•

• antibiotic treatment rarely successful

• provide good quality feed • properly dispose of deadstock • keep pregnant ewes away from sick lamb area

• this is an emergency situation, (contact vet) but if the animal is treated quickly the prognosis is good • intravenous thiamine injections • separate animal during recovery

• consider adding brewer’s yeast to grain rations • avoid feeding mouldy hay • provide adequate water and water analysis

• • • • •

Polio Encephalomalacia

• • •

Cause/Transmission • bacteria in soil (Clostridium tetani) enters body through wound and produces a toxin which damages nervous system • bacteria grows in absence of oxygen, therefore deep puncture wounds are problematic • most often seen in lambs after castration or docking (elastrator bands and contaminated knives) most often seen in feedlot lambs, but also • bacteria (Listeria possible in animals of any age monocytogenes) forms abscesses in brain depression, off feed, fever one side of the body is affected (face paralysis, • contracted from infected sheep through cuts droopy ear, lip and eyelid) • spoiled feed (particularly animal walks in a circle silage) often implicated convulsions, death diagnostic lab can identify bacteria and examine brain for abscesses seen most often in feeder lambs • not known for certain, but thought to be a deficiency of non-infectious (no fever) thiamine (vitamin B1), due to may see blindness, staggering, head pressing, microbes in the rumen depleting progressing to convulsions, coma, and death thiamine supplies (can be provided in diet but not available to the animal) • high mineral content in water may be a contributing factor • deficiency will eventually give rise to neurological disorder

Neurological Disorders Disorder Scrapie

Rabies

Maedi-Visna (see Respiratory Diseases for details)

What Do you See? • relatively rare, but reportable disease • long incubation time, animal may be infected at birth but no signs until sheep is 2yrs or older • typically extensive loss of wool due to rubbing • uncoordinated, muscle temour, twitching, grinding teeth, convulsions • some sheep die quickly with few signs, most die within six months of first signs • diagnosis only confirmed by lab exam of the brain after death • restlessness, twitching lips, excessive drooling (note: not all drooling animals will have rabies, often may be an obstruction in the throat or mouth, however, always wear gloves if you may come in contact with salvia) • animals may act either excessively docile (depressed form) or aggressive butting against wall or fence etc.

• males may show sexual behaviour • animal is progressively paralyzed and generally dies within six days • Maedi-Visna has a respiratory form and a much less common neurological form (very rare in North America) • staggering, gradual paralysis

Cause/Transmission • prion disease (abnormal protein in body which builds up in nervous tissue) • transmitted to lambs and older sheep that come in contact with placenta and birth fluids of an infected animal

Treatment • no treatment • reportable by law, contact your vet immediately if you suspect your flock may be infected

Prevention • careful screening of breeding stock sources • voluntary federal scrapie program is in development to identify flocks at risk of infection, may involve liveanimal test and/or testing for genetically resistant animals

• viral disease which attacks the central nervous system • usually contracted from the bite of an infected animal (dog, fox, skunk etc.)

• none • reportable disease, contact your veterinarian immediately

• no vaccine for sheep • vaccinate farm dogs annually • control populations of potential carriers (foxes, skunks etc.)

Notice to Industry: Animal Health Starts on the Farm (Ontario Sheep News, June 2010) The Canadian Food Inspection Agency (CFIA) is reminding livestock producers of the pivotal role they play in protecting animals from serious diseases such as Foot and Mouth Disease (FMD), which has been kept out of the country for over half a century.

The recent outbreaks of FMD in Japan and South Korea are strong reminders of the importance of practising sound on-farm biosecurity. Both countries had been considered free of FMD— Japan since 2000 and South Korea since 2002.

Producers can take simple steps such as limiting access to animals, closely monitoring the health of the herd or flock, and immediately reporting any suspicion of illness to a veterinarian.

Producers should also ensure that student and seasonal workers are fully aware of farm biosecurity protocols, and report if they have visited, or are planning to visit, another farm. Farm workers or visitors who have recently been in countries where FMD has been detected should not be allowed access to livestock for at least five days after entering Canada.

The CFIA takes decisive action to limit the potential risks to Canadian livestock of FMD outbreaks in other countries. The Agency does not allow imports of susceptible animals and animal products from countries that are not recognized as being “free of FMD,” unless the products have been processed in a manner that destroys the virus.

A list of countries that are recognized by Canada as being free of FMD is available on the following web page: www.inspection.gc.ca/english/anima/heasan/pol/ie-2001-18e.shtml.

Travellers entering Canada from any country are required to declare all animals and animal products. They must also report if they have been on a farm or exposed to animals while in another country, or if they will be visiting a farm while in Canada.

FMD is a contagious viral disease that affects a range of animals including cattle, swine, sheep and goats. The virus can survive on footwear, clothing and equipment for up to five days. There is no human health or food safety risk associated with FMD; however, it can have devastating impacts on animal health and the livestock sector.

For more information on the measures you can take to protect the health of your animals, visit www.inspection.gc.ca/biosecurity. More information on FMD and the CFIA’s disease control activities is available at www.inspection.gc.ca.

For any of the above information, you can also call the CFIA toll-free at 1-800-442-2342.

National On-Farm Bio-Security

Interview with with Dr. Lorne Jordon, Canadian Food Inspection Agency

A

lthough bio-security practices have been employed on Canadian farms for many years, only recently has the term become common in producer literature. Outbreaks of animal diseases, and the recognition of new diseases, have highlighted the need for an examination of on-farm biosecurity practices at a national level. The Canadian Food Inspection Agency (CFIA) responded to this need by creating the Office of Animal Bio-Security (OAB). They’re currently developing national bio-security standards, protocols and strategies for animals and plants, in collaboration with industry, provinces and Agriculture and Agri-Food Canada.

Dr. Lorne Jordan is a Chief Bio-Security Specialist with the OAB and has more than 20 years experience working in the field of infectious diseases. The Canadian Sheep Federation spoke with Dr. Jordan about bio-security and what practices sheep producers can take at home on the farm.

What does bio-security mean?

The term is used in several ways, depending on the context. The OAB is principally concerned with farm level bio-security, which refers to those practices that prevent or mitigate disease-causing organisms from entering, spreading within or being released from premises. The principles of farm-level bio-security are applicable across many sectors of agricultural production, including animal and plant.

Where should bio-security measures be implemented?

Ideally, bio-security measures should be in place not only on farms but at agricultural markets, auctions, research laboratories and international borders. They are also relevant for industries such as feed suppliers, animal transport and abattoirs.

Why is bio-security important?

The spread of infectious diseases costs producers money.

Disease can reduce your feed efficiency, decrease milk production, increase reproductive losses and sometimes cause death. In addition to the direct production losses, producers may incur expenses related to the use of antibiotics, increased labour costs associated with animal treatment, and potential loss of market opportunities. Bio-security practices are important because they work to lessen the spread of infectious diseases, thereby working to save producers money and maintain market access.

What are some of the practices farmers can do to increase bio-security on their farms?

There are certain principles of farm-level bio-security that are applicable to all farms, regardless of type and size.

These include access management – restricting access to the 14

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farm to only authorized personnel; good signage on the farm and appropriate fencing. Good animal health management practices should be applied to all animals on the farm. As each circumstance and farm is different, producers should consult with their veterinarian on which bio-security practices will work best on their operation.

What precautions should farmers take with regards to bio-security before adding new sheep to their flock?

Shepherds should employ the followings steps before bringing new sheep into their flock: • Purchase from reputable breeders.

• Know the health status and vaccination history of the animals being considered for entry. At minimum, this should involve close inspection of new stock and the farm of origin. In some cases, a veterinary inspection may be a good idea and testing for particular diseases may be required (e.g. Q-fever and scrapie resistance).

Upon arrival at the farm, new entries should be quarantined before being placed within the flock (including the use of separate feed troughs). Producers should examine for signs of disease at least daily. Ideally, producers should attend to already resident animals before dealing with the new arrivals.

If moving from new animals to resident animals, change/clean boots and coveralls.

Should farmers take special precautions when showing sheep?

Farmers should ensure that only healthy sheep are taken to shows, this protects both their own stock and others at the show. While at the show, attempts should be made to minimize direct contact between livestock, especially nose-tonose. Cross-contamination with manure and bedding should also be avoided. Handling of sheep should be limited to one’s own animals, and simple personal hygiene measures such as hand disinfection, should be used. Upon returning home from the show, animals should be isolated or quarantined from the rest of the flock.

Should farmers take special precautions when shearing sheep?

Basic bio-security principles should be employed, such as shearing sick animals last, ensuring equipment is clean, avoiding transfer of manure from pen to pen, and treating any cuts that occur in a prompt fashion. If using a commercial shearer, ensure that his/her equipment is sanitized or use yours (if available), and ensure that he/she has clean boots and coveralls.

Should farmers limit access to their farm or flock for bio-security reasons?

Yes, producers can apply simple procedures such as designating controlled and restricted access zones. Post signs and protocols around the farm so these areas are well-marked and known. Where access is essential, the use of designated footwear and outer clothing can be employed.

Vehicle access should also be restricted, particularly for vehicles that may have been on other farms.

What can happen if producers do not pay attention to bio-security?

If bio-security procedures are not a component of farm management, there is a heightened potential for the entry and spread of infectious disease on the farm. As explained above, this has financial implications for the producer. Poor biosecurity practices can also lead to the release of infectious agents off the farm, which could potentially have negative results for other producers. Depending on the disease, human health may also be affected, potentially placing people, including the farmer’s family and staff, at risk.

Is there anything else in general you would like to say about bio-security?

A bio-security plan is one of the best investments producers can make. Although preventive measures are not new to Canadian farms, we are asking all sectors of the industry to look at their bio-security practices in a formal manner, ideally with their veterinarian. Improving bio-security at the farm-level will, in turn, enhance regional and national levels of bio-security.

To assist producers, general principles of bio-security can be found on the Canadian Food Inspection Agency website at www.inspection.gc.ca. OSN This article was provided by the Canadian Sheep Federation, POV Jan 2010, Volume 4, Issue 1

Current ProduCers on Maedi-Visna ProduCer naMe Robert & Gail Irvine Joanne T Ted Skinner Bryan & Janice Lever Robert & Shirley Graves Perry & Christina Sisson Heather & Robert Kelly John & Eadie Steele Glen & Sharon Duff Neil & Heidi Bouman Axel Meister William MacTaggart Gordon Walker Garry & Beth Collins Tina Harrington Colleen Acres Gerald & Joanne Hunter Bethane Jensen Francis & Elaine Winger George & Diane Kydd Darryl & Rachel Stoltz Riva Berezowski & Steve Vidacs Ted Brown Fred Baker Gary Lapier Bert Henderson Jennifer Woodhouse Karen Hayward William Jeffrey Harry & Eleanor Pietersma

FarM naMe Rocky Lane Farm Cedar Creek Charollais Windblest Farm Century Lane Farm Sisson Sheep Farm Greenwood Farm Duff Farms Wooldrift Farm MacTaggart Suffolk Orchardview Farm Collins Horned Dorsets Stonehill Sheep Maple Meadow Farms Hunterdown Farm Shepherd’s Fold Highlands of Tara-Grey Excel Ewe Genetics Cedar Ridge Farm Brown Woolies Farm Hawkwind Farm Rocky Hyland Farm Trillium Woods Sheep Elysian Fields

telePhone 705-292-7207 905-263-2102 613-259-5484 613-831-2656 705-277-2887 519-369-5396 705-696-1491 519-856-9935 519-750-9928 519-538-2844 519-824-3878 519-287-5085 519-934-3239 519-794-3732 613-826-2581 613-283-7565 519-887-9948 519-323-3531 705-277-1274 519-887-8216 519-371-7314 905-877-2323 613-989-5352 613-989-2792 613-346-5980 519-599-5379 519-371-8487 519-234-6872 613-652-2044

Current ProduCers on ontario sheeP health PrograM ProduCer naMe Bill & Lyne Duffield Robert & Gail Irvine Francis & Elaine Winger John & Eadie Steele George & Diane Kydd Colleen Acres Darry & Rachel Stoltz Anne Dockendorff Wietza & Leny Raven

FarM naMe Codan Suffolks Rocky Lane Farm Highlands of Tara-Grey Maple Meadow Farms Excel Ewe Genetics Silver Rapids Farm Green Hill Farm

telePhone 519-899-2663 705-292-7207 519-323-3531 705-696-1491 705-277-1274 613-826-2581 519-887-8216 705-724-9183 519-928-2705

sheeP ProduCers on the sCraPie PrograM ProduCer naMe Bill McCutcheon Axel Meister Bill & Lynne Duffield Francis & Elaine Winger Mels & Ruthanne van der Laan Riva Berezowski & Steve Vidacs Peter Carrie & Susan McDonough Glen & Judy Porteous Paul Dick & Tina Harrington Nicole Heath Bryan & Janice Lever Brad & Gerald Miller Roger & Julie Harley Robert & Shirley Graves & Sons Sara & Jamie Scholtes Joshua & Melissa Groves Chris Wiltshire Leigh Nelson & Luc Pouliot Karen & Jim Hayward Robert & Laurie I’Anson Chris Kennedy

FarM naMe Mulmar Vista Farms, Grand Valley, Ontario Wooldrift Farm, Markdale, Ontario Codan Suffolks, Wyoming, Ontario Mount Forest, Ontario Cold Stream Ranch, Denfield, Ontario Cedar Ridge Farm, Owen Sound, Ontario Smokey Creek Farm, Arthur, Ontario Stonehill Sheep, Chatsworth, Ontario Veliraf Farm, Conn, Ontario Windblest Farm, Lanark, Ontario Miller Farms, Kerwood, Ontario Keene, Ontario Century Lane Farms, Stittsville, Ontario Harmony Marsh Farm, Bailieboro, Ontario VanGro Farms, Brantford, Ontario Iternal Impressions, Bath, Ontario Bent Willow, Kapuskasing, Ontario Trillium Woods Sheep, Shallow Lake, Ontario St. Catherines, Ontario Topsy Farms, Stella, Ontario

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Nutritional Disorders Disorder Copper (Cu) Toxicity

What do you See? • may not be apparent for some time that over consumption of copper is occurring • sudden onset generally after a stressful event (transport, handling etc) • signs include: rapid breathing, yellow tinge to skin and membranes; dark brown urine • most affected sheep die

Cause/Transmission • sheep are much more susceptible to copper toxicity than any other livestock species • excessive intake of copper over a period of time causes a build up of copper in the liver • liver reaches a maximum holding capacity (1-3 g of Cu/kg liver), may take 30-100 days • as a result of stress, the liver suddenly releases stored copper resulting in the break down of red blood cells and jaundice

Treatment • may not know until an animal dies; if diagnosed in post mortem as copper toxicity, treat flock to prevent more • identify and remove the source of high Cu (cattle rations, high-Cu mineral mixes, licks, drenches, corroding Cu water pipes, Cu-contaminated pasture).

• add Cu-antagonists to the diet of the "at-risk groups" for 4-6 weeks. The best researched antagonists are Molybdenum (Mo), Sulfer (S), Zinc (Zn) and Iron (Fe) (veterinary prescription)

White Muscle Disease

• most often seen in newborn lambs, but may also occur in feeder lambs that have not grazed green forage for more than three months.

• depends on muscle groups affected may see: Stiff gait, difficulty getting up, unable to lift heads or suckle, rapid breathing, sudden death • lambs are prone to starvation, pneumonia, diarrhea • most often seen in ewes, 4-6 weeks after lambing • relatively uncommon • affects animals recently turned onto pasture • animal is uncoordinated (staggers), muscle twitching, may have convulsions (legs remain rigid)

• degenerative muscle disease • deficiency of selenium (Se) interferes with the transport, storage, and usage of vitamin E in the body • seen in areas that are deficient in Se in the soil and therefore in forage

• injection of Se-tocopherol (Vit E) • consult with veterinarian on specific product information

• deficiency of magnesium (Mg), and possibly calcium (Ca), and high potassium (K) levels • some areas are naturally low in Mg, therefore decreased in forages • heavy applications of nitrogen also interferes with plant ability to take up Mg • lush grass forage may also decrease Mg absorption by animal • also considered a metabolic disorder

• emergency treatment with Mg and Ca solutions (consult your vet) • recovery occurs quickly if treated in time

Grass Tetany

Prevention • be aware of copper levels in supplements (don’t allow free access to supplements intended for other types of livestock) • avoid using slurry from hog farms on fields used to produce feed for sheep (high in Cu) • total Cu Intake by sheep should be no more than 8-15 mg Cu/kg feed dry matter basis; this can generally be supplied in the diet, without Cu added to a mineral supplement.

• have your feeds analyzed • avoid using forages grown on fields fertilized with hog manure (often high Cu output). If this is unavoidable, have soil and feed tested for Cu • ensure ewes have sufficient Se in diet during pregnancy • if soil is deficient (determine through feed analysis) provide commercial trace mineral mix with Se • if ewes are not supplemented nutritionally, inject ewe and lamb after birth with Se/Vit E solution • if it is a problem test soil and forages for Mg content • consider legume/grass combination for pastures (legumes convert nitrogen and provide higher mineral levels) • soils with low Mg can be upgraded by application of limestone or supplement animal’s diet • apply fertilizer at recommended levels

Nutritional Disorders: Poisonings (often cause signs of neurological disorders) Disorder Plant Poisonings

Nitrate poisoning

Farm yard poisoning

Urea Poisoning

What do you See? • most plant poisonings are characterized by signs such as: • sudden death • laboured or very rapid breathing • frothing at the mouth and excessive salivation, weakness, inability to stand • convulsions or erratic behaviour, greenish saliva (vomiting) • coma • other plants (e.g. St. John’s wort, trefoil, certain clovers) cause animals to become sensitive to light (skin not covered by wool is burnt, inflammation and eventually sloughs) • dark skinned sheep less affected than light skinned sheep • red clover may cause infertility in ewes if fed during the breeding season • animals fed heavily fertilized immature crops • acute cases: increased heart rate, mucous membranes are bluish (gums etc.), muscle tremours, coma, death • chronic cases: reduced performance, decreased milk production, reproductive problems • varies with cause

Cause/Transmission • plant poisoning is not likely to occur on cultivated grounds or well managed pasture.

• most poisonous plants are unpalatable and livestock rarely eat them when other forage is abundant.

• More prone to eat poisonous plants when other plants are not available (in the spring and fall, during a drought or on an overgrazed pasture).

Treatment • treatments generally ineffective by the time the sheep is found

• nitrate altered to nitrite in blood stream, decreases oxygen transfer to cells • increased risk during droughts or if plants are stressed (accumulation of nitrates in plant)

• acute cases have a poor prognosis • change diet for chronic cases

• apply fertilizers at recommended rates • consider testing forages • monitor closely if decreased plant growth likely

• paint, batteries, smelters • pesticide (incecticide, herbicide, rodenticide etc.)

• varies with cause, contact your veterinarian

• affects animals being fed urea in diet • uneasiness, tremors, excessive salivation, rapid breathing, uncoordinated, bloat.

• improper mixing of urea supplement into a grain ration • sudden increase in urea supplement in diet • excess urea broken down into ammonia which is absorbed into the bloodstream – as with nitrate poisoning

• call a veterinarian to treat cases of urea toxicity • as an emergency measure, vinegar may be administered as a drench - lowers rumen pH and neutralizes ammonia

• keep the barn yard, sheep pens, and pasture free of toxic materials • prevent exposure to freshly paint • clean up or fence off garbage sites that sheep may access.

• follow label instructions when adding urea supplement to the diet

• sheep affected with signs of light sensitivity should be removed from vegetation • provide sheds or shade is available • if severe, burned areas can be treated with antibiotic ointments

Prevention • prevention much more effective than treatment • don’t overgraze pastures • have plenty of drinking water, calcium, phosphorous and mineral mix available at all times to prevent depraved appetites.

• manage pastures to discourage weeds • a list of poisonous plants found in Ontario is available from OMAFRA

Common Disorders Affecting Sheep in Ontario Causes of Disease Health disorders include all diseases and conditions that compromise the productivity and well-being of your sheep. The causes of disorders can be broken down into two basic categories: infectious (transferred either directly from an infected animal or through contact with an object contaminated by an infected animal) and non-infectious (environmental causes). Subcategories of the two basic types of diseases have been briefly described in the following two tables. Although they have been separated, more than one cause may affect an animal at a given time. Indeed, many of the infectious agents are opportunistic and will flourish only when an animal is weakened due to another problem. For example, under normal conditions sheep are exposed to a wide variety of viruses, bacteria, fungi and parasites.

However, they may remain healthy unless their immune system is compromised due to environmental stresses, such as poor nutrition or inadequate housing. The connection between good management and health cannot be stressed enough, as a little prevention can dramatically protect your sheep and your pocketbook from debilitating diseases.

Infectious Disorders

Infectious General Information Agent Bacteria • single-celled microorganisms that exist either independent (free-living) or as parasites (dependent upon another organism for life).

• many dependent bacteria in the body are synergetic (depend on the host, but contribute to the animal as well-e.g. rumen microbes) • two general types of bacteria based on lab methods for classifying (gram positive and gram negative), this is important when deciding which type of antibiotic to use, as particular medications will only be affective against particular organisms. A gram positive specific antibiotic will have little effect against gram negative bacteria. Some antibiotics are broad-spectrum meaning they cover a large number of bacteria types.

• antibiotic resistance occurs naturally as bacteria come in contact with the drug.

Antibiotic resistance is a major concern for both animal and human health. Improper use and overuse of antibiotics will greatly decrease the length of time that antibiotics will be effective Virus • smaller than bacteria and cannot grow or reproduce apart from a living cell. A virus invades living cells and ‘commandeers’ the cell structures to replicate. The cell is often destroyed as the virus replicates • high rate of mutation during replicating means that characteristics of virus populations can change rapidly, making development of treatments difficult • antibiotics do not affect the progress of the diseases caused by viruses. At times a secondary bacteria infection may develop in an animal that is weakened by a viral disease. In this circumstance antibiotics will be useful.

• vaccines have been developed to protect against some types of viruses • for some (e.g. Meadi-Visna) blood tests have been developed to detect the presence of the virus in the body • some viruses will eventually be cleared from the body by the animals immune system, other viruses, once caught, will always be present Parasites

Examples Clostridial diseases, foot rot, some types pneumonia, some abortion diseases

Foot and Mouth, sore mouth, rabies, MaediVisna

coccidiosis, worms, keds

Prion

• prions are proteins normally found within the body’s nervous tissue (nerves, spinal column, brain) • for unknown reasons these prions at times will change to a form that resists the normal mechanisms for turn over and break down • prions continue to build-up on the nerve tissue eventually causing nervous disorders

Non-infectious Disorders Type Information Nutritional • deficiency or excess of particular nutrients in the diet • can be acute (occur suddenly), but most often is a gradual depletion or build-up of nutrient Metabolic

Digestive Genetic

• closely tied with nutritional disorders as they are caused by an imbalance in the nutrients supplied in diet with production demands • animal’s metabolism can not meet the production demands and nutrients are extracted from the animal’s system at a greater rate than they can be replenished • typically rapid onset of signs • occurs at times of sudden increases production requirements (e.g. when a ewe begins lactating) or with sudden changes in diet (e.g.hay diet directly to lush pasture) • also linked with nutrition and changes in diet • generally caused by a disruption in rumen function • defects which are inherited from parents • intensive line-breeding or inbreeding programs generally cause an increase in these disorders • keeping good breeding and lambing records will greatly aid in culling the problem out of your flock

Scrapie

Examples White muscle disease, photosensitivity, copper toxicity Pregnancy toxemia, hypocalcaemia, grass staggers

Bloat Entropion, overshot jaw

Diagnosis of Sheep Diseases Over time most producers become adept at recognizing and treating common livestock health problems. You should try to learn as much as possible about common diseases and their signs and treatments.

If you are confronted with an unfamiliar disease or are uncertain how to handle the situation, consult with your veterinarian. Quickly determining what the problem is and how to treat it may help prevent a major and costly disease outbreak. During the initial phone call to your vet, be sure to have a list of the disease signs on hand. With enough information your vet may be able to make suggestions without making a visit, particularly if he/she is very familiar with your flock management practices. A farm visit, however, may be necessary for the vet to completely assess the situation. As well as providing insights into how to treat the current situation, your vet may have valuable suggestions for preventing future occurrences.

Occasionally animals will die; this is a normal part of framing. However, you should make every effort to determine the cause of death to help prevent the problem from reoccurring and to possibly prevent more losses. Some producers may wish to do a partial post-mortem on the animal themselves to determine if there are any obvious internal signs of disease (e.g. lung abscesses, pulpy kidney etc).

Producers may wish to send samples to a veterinary pathology lab for a complete post-mortem. This is particularly important if there have been multiple cases of unexplained deaths or abortions on the farm.

As well as looking for visible and microscopic disturbances in body tissue, the pathology lab will be able to develop bacterial cultures to help pinpoint the exact disease cause. Samples are generally sent on referral from your farm vet (i.e. your vet will officially request the post-mortem and provide his/her own

observations at the time of submission). To obtain accurate results, the submitted sample must be fresh and/or well preserved (i.e. half decayed samples will yield an invoice, but very little useful information).

Samples can generally be refrigerated, but not frozen, to help maintain tissue integrity. The status of slowly progressing diseases may be monitored by occasionally sending older, cull animals to the pathology lab for analysis. In Ontario, the Animal Health Laboratory at the University of Guelph (519824-4120 ext 54544) and a satellite lab at Kemptville College (613-258-8320) provide testing. Some private veterinary clinics may also provide some services.

Reportable Diseases:

There are several diseases that occur in sheep that are reportable by Canadian law. If you suspect that your flock may have one of these diseases you must report it to your veterinarian, who will forward the information on to the federal authorities (Canadian Food Inspection Agency). Reportable diseases that have been known to occur in Canada include, anthrax, anaplasmosis, bluetongue (BC only), brucellosis, foot and mouth disease, rabies, scrapie, and tuberculosis.

Johne's Disease in Sheep

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Johne's Disease in Sheep

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Introduction World-Wide Distribution Johne's and Humans?

The Agent The Clinical Disease How the Disease is Spread in the Flock Other Methods of Transmission Diagnosis Other Diagnostic Tests Control & Eradication The Cost of Disease Preventing Introduction So Where Do We Go From Here?

Introduction

Johne's disease (pronounced yonee's) is a disease of ruminants characterized by wasting and terminally, by diarrhea. It is caused by a bacteria called Mycobacterium avium subspecies paratuberculosis. Johne's disease has been reported in Canada in cattle for several decades. Although it has also been reported in sheep for many years, no one is certain of how widespread it is or exactly how much damage it is doing to our sheep industry.

WorldWorld-Wide Distribution Johne's disease has been diagnosed in cattle (both dairy and beef), goats, deer (fallow, red deer, white tail deer and many other species both wild and farmed), llamas, camels, other wild ruminants (moose, Rocky Mountain goats, bison, antelope, big-horn sheep) as well as sheep. The disease in sheep has been reported across North America and Europe (including Iceland). It has been a major infectious disease of sheep in New Zealand for some years but has only invaded Australia in the last decade, where it appears to be spreading rapidly.

Reports of experimental infection of non-ruminant species such as mice and rabbits has led to speculation that there could be non-ruminant reservoirs of disease, particularly in the United Kingdom (UK) rabbit population.

Johne's and Humans?

In recent years there has also been speculation that M. avium subsp. paratuberculosis may also be implicated in Crohne's disease in humans. This is a disease characterized by ulceration of the intestine causing extreme pain and debilitation. While it may be an autoimmune disease, special tests that detect DNA (Polymerase Chain Reaction tests) have detected evidence of the organism in some Crohne's patients. However, to date this research has not been confirmed and the organism has not been cultured from human cases. In addition, Crohne's disease has been reported in parts of the world that do not have Johne's

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disease (e.g. Western Australia). The jury is still out on this one. | Top of Page |

The Agent There are three major strains of this bacteria (which is related but different from Mycobacterium avium subsp. avium, a disease of birds and rarely humans [avium tuberculosis]). There is a cattle strain, a sheep strain and an intermediate strain. While cattle are susceptible to all three strains, they are usually not infected with the sheep strain. Sheep usually get only the sheep strain but can also succumb to the intermediate strain. Goats usually have the cattle strain. Â

The Clinical Disease

Text Equivalent of Figure 1 Johne's disease in a flock or herd behaves very much like an iceberg. The disease that a shepherd may see in the flock represents only a small proportion of sheep that are actually infected. The age at which the disease becomes visually evident (i.e. wasting) likely reflects the amount of infection in the flock. If ewes are two to three years old when they become ill (as opposed to four and older), it indicates that there is a fairly high prevalence of infection in the flock, and thus a large environmental load of bacteria.

Sheep can become infected at any age, but if infected while a lamb or fetus, then the disease manifests itself as young as 18 months. An astute shepherd may notice nothing more than a ewe that seems to be a little thinner than the rest of the flock. Sometimes another stress such as lambing or mastitis will hasten the onset of more severe clinical disease. The ewe is depressed and pale and very thin and about 20% of cases develop

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diarrhea. Diarrhea indicates that the sheep is nearing the end and will die soon. Thin sheep are usually culled or buried (if they die or go down due to weakness) rather than necropsied by a veterinarian. And so the disease may go unnoticed for many years.

A necropsy at this time would reveal greatly enlarged intestinal lymph nodes filled with Johne's bacteria. Intestinal changes may be mild to moderate with thickening of the gut wall.

Often the lesions are quite subtle and they require the keen eye of a trained pathologist to pick up the signs. Many producers and butchers will miss the lesions.

This difficulty with diagnosing the disease is why several cases often occur in the flock before the disease is detected. By that time, the environment and several generations of sheep have been exposed to the bacteria in large doses.

Johne's disease may also be mistaken for other wasting type diseases. Bad teeth due to incisor loss (broken mouth) or uneven molar wear and gingivitis can cause considerable weight loss. Maedi Visna can cause wasting. Parasites can drag down even an adult ewe and diarrhea will further confuse the diagnosis. Internal abscesses due to caseous lymphadenitis can also cause wasting with few other clinical signs. And of course, periodic poor nutrition (e.g. poor pasture or hay) or excessive competition can lead the producer to make excuses for the thinness of some ewes. | Top of Page |

How the Disease is Spread in the Flock Typically sheep become infected through eating feed contaminated with fecal material. The bacteria invade the intestine and the intestinal lymph nodes where they become established and interfere with absorption of nutrients, hence weight loss. This progression, however, takes two to seven years to go to completion, depending on the number of bacteria that infect the sheep and the age at which the sheep is infected.

When they are first infected, sheep do not shed the bacteria. This period of grace may be as short as a year or as long as 5 yrs but is often 2 to 3 yrs. Eventually the infection progresses to the point where bacteria are shed in the feces although the sheep still appear healthy and productive. This period of bacterial shedding without clinical disease may last a year or better. An infected, shedding animal may, for the time being, be the most productive ewe in the flock.

The bacteria have a very thick cell wall and can survive in the environment for perhaps as long as a year. They are resistant to disinfectants and to drying by the sun. Infected sheep on pasture will contaminate that pasture for other grazing animals. Infected sheep in a barn may defecate into feeders or waterers. Lambs born into these contaminated environments are most susceptible to infection. Dirty udders and wool tags, barn yards, bedding, etc are all sources of infection to the curious lamb. Plowing infected grazing land will dilute the bacteria and help to kill them. Snow cover will help their survival whereas sunlight, drying or exposure to intense cold will reduce their numbers. Disinfectants must be suitable against mycobacteria to be effective against Johne's bacteria. Few disinfectants work well if used in the presence of organic material. Â

Other Methods of Transmission During Pregnancy

Although Johne's disease is primarily a disease of the intestine, during the advanced stages of disease the agent may spread throughout the body. Fetuses are very susceptible to infection while still in the womb. Lambs may be born infected (in cattle, up to 60% of calves

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born to cows in advanced disease, were infected) and these animals may develop clinical disease at an earlier age. This means that even removing lambs at birth will not guarantee freedom from infection if the dam is infected. Milk and colostrum sometimes have small numbers of organisms present but it is not known how important milk is as a source of infection.

Semen

In cattle, the bacteria have been isolated from semen from bulls with advanced Johne's disease. To date there is no report of infection of a cow or calf from infected semen although bulls are screened in AI units. An infected bull on a farm is far more likely to infect other animals from contamination of the environment than from infected semen. In sheep, the risk is likely low, particularly when using AI since the semen is diluted.

Embryos

Embryos are free from Johne's bacteria. In a severely infected flock, embryo collection may give one of the best opportunities for preservation of valuable genetics, even when the donor ewe or ram are heavily diseased. | Top of Page |

Diagnosis Direct Examination

The first diagnosis is often made at necropsy. As mentioned before, the intestinal lymph nodes become enlarged and the intestinal wall may appear thickened. Signs in sheep are more subtle than in cattle, in which the large intestine becomes quite thickened and corrugated like cardboard. Bacteria can be stained and viewed by a microscope. Sometimes the bacteria can be seen in a fecal smear, particularly in animals that have reached the diarrhea stage. To be diagnostic however, large numbers of bacteria must be seen and follow-up tests need to be done.

Bacterial Culture

This is not very successful in sheep. In cattle and goats, the bacteria can be cultured about 60% of the time when they are present in the feces. However, the bacteria are very slow growing and take 4 to 16 weeks to grow. This means that negative results take at least 4 months and then a negative result may only mean failure to grow or that the animal is still in the early stages of disease. The situation in sheep is even worse. Diagnostic laboratories in North America and elsewhere seem unable to grow the bacteria with any degree of success.

Sensitivity of bacterial culture in sheep even when showing severe clinical disease is only 8% (8 animals culture positive out of 100 shedding animals). The result is that we don't even try to culture bacteria from sheep.

Serological Testing

Many serological tests are used to detect antibodies to M. avium subsp paratuberculosis. In sheep the most commonly used test is an Agar Gel Immunodiffusion Test (AGID). While a positive test result is generally correct, animals in the early stages of disease or in the advanced stages will often test negative. This means that AGID test rarely classifies a healthy sheep as infected (few false positives) but may misclassify many infected sheep and call them healthy (many false negatives).

Sheep shed bacteria in the feces for three to nine months before testing positive to the AGID test. The sensitivity for subclinical animals is less than 30% (3 out of 10 infected animals classified as infected) and is only 50% (5 of 10 infected animals classified as infected) in clinically affected animals. Animals in advanced disease sometimes lose the ability to

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respond to disease because of debilitation.

Many ELISA tests (Enzyme-Linked Immuno Sorbent Assay) have been developed with an aim to improving the ability of the test to detect diseased animals. However, infected animals still slip through and sometimes animals infected with non-pathogenic Mycobacterium sp. will test positive, further confusing the picture. | Top of Page |

Other Diagnostic Tests DNA probes are diagnostic tests that detect specific DNA. Live organisms do not have to be present, just DNA remnants. Specificity can be quite good with these tests, i.e. doesn't crossreact with other types of DNA and sensitivity can be variable. When DNA probes to M. avium subsp. paratuberculosis are used in the feces, approximately 1,000 to 10,000 bacteria per gram of feces are required to reliably detect the bacteria, compared to only 100 bacteria per gram for fecal culture (cattle data). It isn't known how well the test works in sheep but may help to detect pre-serologically positive cases. The drawback is that not all veterinary diagnostic laboratories have the correct equipment and the test is expensive to run.

There are also tests that detect cell mediated immunity (as opposed to antibodies). One is a skin test using delayed type hypersensitivity (DTH) like the TB test commonly used in humans. The second is a lymphocyte stimulation assay. The DTH test has problems with cross-reaction with other M. avium species that aren't pathogenic. One type of lymphocyte stimulation test (called the gamma-interferon assay) is being explored as a commercial test for cattle but hasn't been evaluated yet for sheep. In cattle, the sensitivity is thought to be between 70 and 94% with excellent specificity (almost 100%). Although there are many diagnostic tests available they all have serious drawbacks which makes early reliable detection of infected animals very difficult. | Top of Page |

Control & Eradication All programs of this type are based on the ability to detect and remove diseased animals and to prevent the spread of disease within the flock. As you can see, with Johne's disease this is difficult because of the poor accuracy of the diagnostic tests. Until the spring of 1995, the Canadian government did have a voluntary eradication program based on serological testing.

It was abandoned, for many reasons but mostly because the program didn't have adequate diagnostic tools. As of the summer of 1997, Johne's disease is not a reportable disease, i.e. the government is not concerned with the reporting, the control or the eradication of this disease. Estimates of prevalence then, are poor and are limited to the number of positive necropsy diagnoses at provincial diagnostic laboratories.

Because sheep producers rarely submit thin ewes for necropsy, choosing instead to market them and pocket up to $60 for a cull ewe, many diagnoses are missed. Flocks that are known to be infected likely have a high prevalence of disease. This makes the thought of eradication quite daunting.

Programs are generally based on annual or semi-annual serological testing (usually AGID) of all sheep greater than 12 months of age. Positive sheep are immediately sent to slaughter and offspring marketed. No animals should be sold where there is a risk of selling them for breeding stock (e.g. auction barns). The flock must remain closed to avoid reintroduction of disease. Often between three and five negative annual tests are required before the flock can be called low risk of disease. In a flock of 100 adult ewes greater than 12 months, at $5.00/sample (a minimum charge) plus costs of bleeding the sheep (likely not less that $150), annual costs of serology alone will be $650.

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The Cost of Disease The cost of disease is not well worked out because it will vary with type of flock (purebred vs. commercial or dairy vs. meat) but an estimate of approximately $90 per clinical case has been reported. This seems low for a purebred flock if opportunity sales are lost due to disease status of the flock. Bovine cases have been estimated at US$2,500 per clinical case.

Preventing Introduction Because eradication is a long, difficult, expensive process, it is much better to prevent the disease from coming into the flock. How does this happen? Almost always this occurs with the purchase of breeding stock, either a ram or replacement ewes. Sheep grazing community pastures could also pick up the disease. Ruminant manure from other farms spread onto pastures or hay fields is a potential source of infection although this practice is unusual. Wild ruminants may be a source but this has not been documented. A purebred ram from an infected seedstock flock, shedding bacteria could breed for a season or even two successfully before succumbing to the disease but his legacy will be left with the flock.

Johne's might not be diagnosed in that flock for up to five years, by which time the source may have been forgotten.

There currently is no national or provincial program for certifying flocks free of Johne's disease. This means that education is our best tool against this disease. Improved biosecurity, which includes closing the flock or purchasing from reputable breeders that will stand behind the health of their flock, is a beginning to slowing the spread of this disease.

Countries like Australia are grappling with the possibility of depopulating infected flocks.

North America does not have a vaccine but endemically infected countries like New Zealand rely on vaccination to control the losses due to clinical disease and are deciding whether to keep the disease reportable. The US is concerned about internal control but there is tremendous variation from state to state with respect to control and eradication. At this point, it is mostly buyer beware, the same as here in Canada, although some producers that have been sold infected cattle are testing the liability waters.

So Where Do We Go From Here?

There are infected seedstock sheep producers in Canada and the US. No program identifies them or protects other producers from purchasing infected stock. It is up to the industry to be concerned about Johne's and other silent, contagious diseases that can rob a flock of productivity and can be purchased in apparently healthy sheep. To prevent the spread of this and other diseases we need to stress producer education, improved biosecurity and eventually a program that can certify a flock as being low risk of disease. | Top of Page | For more information: Toll Free: 1-877-424-1300 Local: (519) 826-4047 E-mail: ag.info.omafra@ontario.ca

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This site is maintained by the Government of Ontario  Queen's Printer for Ontario Last Modified: April 15, 2008

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Administration of medication to sheep Tips For Using Antibiotics Antibiotics are, of course, only one type of the medications that you may use to treat sheep. However, with recent concerns regarding the use of antibiotics for livestock production, it is important keep in mind how and when to use this type of medication. Using antibiotics responsibly helps maintain the effectiveness of these important drugs and helps producers save on medication costs. Some basic rules when using antibiotics are listed below: 1. As a producer, know what diseases are prevalent at particular production stages or seasons. Consult your veterinarian if you are uncertain about the diagnosis.

2. Recognize the limitations of antibiotics. Remember that some bacteria are only sensitive to certain antibiotics, and that antibiotics are not effective against diseases caused by viruses. An antibiotic will not remove scar tissue from lungs, and there is no advantage in treating some animals with persistent respiratory problems.

3. Take the sheepâ&#x20AC;&#x2122;s temperature. If the temperature is normal (101-103°F), the cause of the disorder is not likely to be due to an infection and antibiotics will generally not be effective.

4. Monitor animals regularly and treat early. Infections are more difficult to treat once they are well established.

5. Follow label or veterinarian instructions regarding dosage and length of treatment. Do not cut the treatment time short even if the animal appears to have recovered. Although it may seem that you will save a dose or two of antibiotic by decreasing the treatment time, in the long run you could be creating even larger problems. The antibiotics may have only had time to curb the bacteria growth, but not completely eliminate the population. The remaining bacteria have a good chance of surviving and becoming resistant to the antibiotic.

6. Identify animals that have been treated. Ensure that everyone that works on the farm understands the identification system and is recording each time medication is administered.

7. Vary antibiotics if the one you are using is not effective after the first round of treatment. Maintain records regarding which medication has been effective in the past.

8. Take care of drugs and store according to label recommendations (e.g. refrigerate, store out of direct light etc.). Watch expiry dates and do not use outdated drugs. Medications that are old or not stored correctly may be less effective at eliminating all of the bacteria (possibly leading to resistance), and in some cases may become toxic to the animal you are treating.

9. Antibiotic residue in meat and milk is a major food safety concern. Maintain records regarding the withdrawal dates of all medications administered to animals. Double-check your records before shipping animals for slaughter. If you accidentally ship animals that have not met the withdrawal dates, notify the buyer as soon as possible.

10. Prevent problems. Do not rely on antibiotics to replace good management. Provide sheep with a dry, clean environment, ample feed and have a biosecurity plan in place.

Injection Methods Prepared by veterinarians in the Veterinary Science Group, OMAFRA Do more good than harm.

Injection is the only method of administration for many medicines and vaccines. Although the purpose of an injection is to benefit your animal, each injection has the potential to do harm, besides pain or suffering. The injection could also create residues, scar tissue, or abscesses. Here are methods of giving vaccines and injectable treatments to avoid problems at injection sites and to maximize the benefits of your treatments.

Read the Label Manufacturers guarantee their products for safety and efficacy when used according to label directions.

Extensive research revealed the best site, route, and dosage for the product. The most common injectable routes are subcutaneous (SQ), intramuscular (IM), and intravenous (IV). Read the label, look for the following information, and follow the directions.

1. The product name, the active ingredient and the concentration appear on the label.

2. The description of its use describes a product and its purpose.

3. The instructions for preparation describe how to prepare a product for injection.

4. The formulation describes the contents of the package and tells you if the product is suitable for injection.

5. Warning statements show hazards to human health from handling the product, the withdrawal time, and restrictions on use.

6. The withdrawal time is the minimum time between the last treatment and the slaughter of the animal for food (or sale of the milk). This is the time needed to allow for residues to deplete to safe levels.

7. Product usage information appears on the side panels of a label.

8. The precautions statements alert you to storage and safe handling practices to maintain stability and potency.

9. The indications statements show the species, class of livestock, and the disease conditions for the product.

10. Dosage and administration statements show the directions for use (e.g. how much, how often, how long), and the route of administration (e.g. IM, SQ, IV), and the timing of treatment.

11. Cautions and contraindications statements warn about hazards to animal health and safety (e.g. known adverse reactions).

12. Restricted uses will appear on the labels of some products. (e.g. do not use in sheep).

13. Read package insert for complete directions , additional precautions or more complete instructions.

14. The expiry date is the date past which the product should not be used. It is valid only if the product has been properly stored.

15. The lot number describes the manufacturerâ&#x20AC;&#x2122;s batch during production. It is used to trace the drug if necessary.

Keep your glasses handy for reading labels. The print is often small.

Bottles and Bottle Tops 1. Clean bottle tops with alcohol and cotton.

2. Place one sterile needle in the bottle top to fill the syringe and use a separate needle for injection.

3. Remove needles from all bottles prior to storage.

4. Write the date the bottle was opened on the label.

The Injection Site 1. Choose SQ when given a choice of IM or SQ on the product label.

2. Choose muscle tissue of lesser value to consumers (e.g. neck) for IM injections.

3. Give SQ injections in the neck in front of the shoulder or over the ribs behind the shoulder.

4. Inject through an area of clean dry skin.

Clean Equipment 1. Wash your hands before and after handling products.

2. Use sterile disposable needles and syringes.

3. If not using disposable equipment, clean and sterilize all equipment before and after use.

4. Use only hot water to rinse syringes before using modified live virus vaccines. Chemicals may destroy the live virus.

5. Use hot water and mild disinfectants to clean syringes for other injectable products.

Needles 1. Use a new, sterile, disposable needle for each animal.

2. If using the same needle for multiple injections, change the needle frequently (e.g. 10 animals) to ensure it is not bent or burred (slight bent at the point).

3. Choose the smallest needle size for the product to minimize tissue damage and reduce leakage at the injection site. Use 16 or 18 gauge needles for most injectable products (20 for lambs).

4. Choose the correct length needle, 1 inch for IM and 0.5 inch or less for SQ sheep.

Restraint Restrain the animal to prevent injury to yourself or the animal, and to prevent needles from breaking off in tissue.

Volume of Injectable Product 1. Inject quantities no greater than recommended on the label (for one dose).

2. Split large volumes into smaller amounts and inject in different locations (e.g. opposite side of the neck).

For IM injections, inject no more than 10 m1 per site. For SQ injections, inject only 20 ml per site.

Multiple Injections 1. Choose different body locations (e.g. opposite sides of the neck) when repeating injections over a number of days.

2. Place repeat injections about 4 inches from a previous injection site. | Needle and Syringe Techniques 1. Eject air from the syringe before injecting the product.

2. After inserting the needle, check that it is not in a blood vessel when injecting IM or SQ. Pull back on the plunger and observe for blood. If blood appears, remove the needle and put it in a slightly different location.

3. Give SQ injections into a tent of skin. Lift a fold of skin and insert the needle through the skin into the tented space. The needle enters the skin at an angle of 30 to 45 degrees to the body. Use a 0.5 to 1 inch long needle.

4. Give IM injections deep into a muscle. Your needle must be long enough to penetrate skin, subcutaneous tissue and fat to reach the muscle. The needle enters at a 90 degree angle to the body. An 1 inch needle will suffice.

5. For IV injections, get advice and training from your veterinarian. Consider enrolling in a Livestock Medicine course (see pamphlet in this chapter) Mixing Products 1. Do not combine vaccines or products unless the label clearly states to do so. Mixing inactivates products through changes in pH, alterations to chemical composition, or precipitation out of solution.

2. Do gently shake or agitate products to ensure that they stay in proper suspension in the bottle. Some products settle out and you need to invert and gently shake the bottles before and during use.

Adverse Reactions Injecting medicines into sites other than the one recommended on the product label can lead to adverse reactions.

Examples include: 1. delayed absorption of the drug, achieving lower than therapeutic levels, and less-effective treatment 2. delayed absorption of the drug and extended withdrawal times due to residues from pooling of the product in tissue; 3. moderate to severe tissue reaction with pain, swelling, interruption of blood supply and delayed absorption of the product, or formation of scar tissue and excessive trim at slaughter; or 4. allergic reactions, shock, or death.

Records 1. Keep records of injections given to your herd or to individuals. (See Chapter 4 for a sample record) 2. Record the animal identification, date, product name, dosage given, the route, the site, and the withdrawal time.

3. Ask your veterinarian for written instructions when medications are being dispensed.

4. Save the box tops or labels with product names, lot numbers and expiry dates.

5. Keep a package insert for reference.

For further information, please contact your local veterinarian.

Injecting Medication: The follow table is intended to give a brief overview of different injections methods. If you are uncertain how to proceed, contact your veterinarian.

Route How to administer When to use Tips and precautions Subcutaneous • follow instructions above for preparing the dose • if both IM and SC are • using a large gauge needle will prevent Injections (SC) listed on the label, loss of medication after injection (hole is • SC injections are given by lifting up (tenting) the skin under front legs or (under the skin) always use SC smaller) on the neck and insert needle underneath the skin (into the ‘tent’) • many vaccines can be • particularly with large doses there may be • insert the needle at an angle, rather than straight across (may go through given this way a lump at injection site, this not a the other side of the skin fold) or straight down (may hit the muscle) generally problem and will disperse.

• on occasion, an abscess may form at site Intramuscular • when giving IM injections always inject into the neck muscles (avoid neck • only use this method if • avoid drugs that are extremely irritating to Injections (IM) bones and shoulder blades). Do not inject into the hindquarters as this may no alternative is listed muscles (into the muscle) result in having high priced cuts of meat condemned due to injection scars on the label or abscesses • pull plunger of syringe back after inserting needle to make sure that the needle did not penetrate a blood vessel. Injecting many medications directly into the blood stream, can cause sudden death Intravenous • before attempting this method have someone familiar with the technique • used in emergency • IV delivers medication to the animal’s Injections (IV) show you what to do situations (pregnancy system very quickly; this is good as it can (into a vein) toxemia, polio, etc.) save animals, but the results of incorrect • most often given in the jugular vein in the neck (in the groove of neck) when medication dosing are also more immediate – be sure • if you are right handed, use your left hand to ‘bridge’ vein (place light administered by other you have the correct dose and medication pressure across the vein to cause a slowing of the blood flow methods will not be • it is suggested to attach the syringe after • vein should bulge above your hand (direction of the animal’s head) absorbed quickly the needle is in the vein to help prevent • with a finger of your right hand, feel for the exact location of the vein enough to save the accidentally inserting the dose into a (feels spongy and springy) animal major artery near the jugular. As arterial • once you’ve located the vein, insert the needle (no syringe) at a shallow blood flows to the cells (including the angle (see tips and precautions) brain), medication in the artery will • the needle should go in with little resistance and blood should flow readily generally kill an animal. By injecting the from the open end of the needle needle without the syringe attached you • carefully attach the syringe and give the dose slowly to avoid shock can assess the blood flow (arterial blood is bright red and will pulse strongly out of the needle; venous blood is darker in colour and tends to flow out of the needle at a steady rate).- If in doubt, do not give the dose.

Udder Infusion • read label instructions • localized treatment of • if you are using cattle preparations, be mastitis sure you use a small size needle to avoid • wash udder and teat and disinfect end of teat with alcohol injuring the ewe’s teat • insert tip of tube or syringe into teat opening and deliver dose • massage udder after injection Intraperitoneally • administration of • do not attempt this method unless you (IP) glucose to lambs have received instruction; adhesions, (Abdominal) infections, and intestinal obstructions can occur

Oral Administration Route Drench

How to administer • always use a proper drenching ‘gun’ • sheep should be standing • stand behind the sheep (if you do not have a chute or an assistant to hold the sheep, you may wish to back the sheep into a corner to prevent it from backing up as the dose is given) • place your free hand under the jaw and hold the head in a natural position, avoid pulling the head too far back or to the side.

• inserted the nozzle of the gun into the side of the mouth over the tongue towards the throat; give the dose gently.

When to use • Used to administer individual doses of liquid medication (i.e. liquid dewormers)

• insert the bolus gun (or balling gun) as given under “drenching” • ensure that the gun is far enough in the throat, and depress the handle of the gun

• Used to administer individual doses of medication in pill form

Stomach Tubing (lambs)

• specially designed tubes are commercially available or any new, flexible (3/8 " diameter) tubing can be used with a 60 cc plastic syringe to deliver the milk.

• lay the tube alongside the lamb and measure from the last rib to the mouth. Make a mark on the tube at this point with a piece of tape or a marker pen, and allow an extra foot of tubing past this point • hold the lamb on your lap and ensure that the lamb’s head is upright (don’t tube while the lamb is laying flat on it’s side).

• put your thumb in the mouth, between the teeth, and gently pry the mouth open.

• insert the tube through the side of the mouth and feed it slowly into the mouth as the lamb swallows. Keep a finger in the mouth while the tube goes down to prevent the lamb from chewing it. Keep passing the tube until the mark on the tube is level with the mouth.

• there may be a small amount of resistance as the tube passes into the throat, however, if the lamb struggles violently or if you can only pass the tube half way to your mark, the tube may have accidentally entered the trachea (windpipe). Pull the tube out and try again.

• attach a syringe full of milk to the tube and slowly inject it (10-15 seconds).

• Giving colostrum or electrolyte fluids to young lambs to weak to suckle

Feed and water

• medicated feed can be purchased premixed from the feed mill. Feed at the • Mostly used as recommended level prophylactic (preventative) • if mixing medication in feed or water on farm, always follow label instructions exactly treatment of certain • check mixing and feed/water distribution diseases (e.g.

• if mixing or administration errors are made, contact your veterinarian coccidosis or shipping fever)

Bolus

Tips and precautions • check nozzles for rough edges that may cause damage to the back of the throat.

• do not insert the nozzle to far into the throat. The trachea (windpipe) lays directly beneath the esophagus (leading to the digestive system). If the liquid is forced into the trachea, the sheep will inhale the drench.

• be sure proper size boluses are used in sheep (big cattle pills could become stuck halfway down and cause choking and bloat).

• depending on the amount inhaled, the sheep may develop pneumonia or suffocate.

• unless it is absolutely necessary, avoid stomach tubing lambs.

When lambs suckle they activate a reflex that by-pass the rumen and leads the milk into the abomasum.

Without this reflex the milk will end up in the rumen possibly cause digestive upset and preventing the antibodies in the colostrum from being properly absorbed.

• do not rely on this method if animals are off-feed • label bins with medicated feed to prevent mistakes in feeding • ensure there is adequate feeder space for all animals in the pen

Oral Administration - con’t Route How to administer Stomach • hold sheep as with drenching tubing • insert a speculum (stiff metal tube) into the throat (don’t force it too far); speculum (adults) prevents the sheep from chewing on the hose • pass a pliable rubber hose (3/4" in diameter and 3 to 5 feet long) through the speculum into the rumen (as with tubing lambs, mark the approximate distance on the hose) • administer medication directly into the rumen

When to use • treating for bloat or other digestive upsets

Tips and precautions • as when stomach tubing lambs, do not force tube if there is undue resistance

Topical Medications This type of medication can be placed directly on the skin for absorption into the system (i.e. deworming medications) or to treat localized infections (eye ointment, antibiotic creams etc.). If you use topical medications, particularly dewormers, ensure that the recommended withdrawal time have been met before allowing the animals to be shorn.

Figure 1: Lamb receiving IM injection.

The Ontario Sheep Health Program What is the Ontario Sheep Health Program (OSHP)?

OSHP is a flock health program developed at the University of Guelph and used as a reference for other sheep health programs across Canada and internationally

How can OSHP help sheep producers?

OSHP uses methods of disease control and flock evaluation proven to increase the efficiency and productivity of livestock operations OSHP promotes a strong working relationship between producers and veterinarians to increase the awareness of on-farm and provincial flock health concerns OSHP can be modified for use on all types of sheep operations Certification in OSHP demonstrates that a producer: follows procedures to ensure on-farm disease control and quality assurance practices commits time and effort into optimizing flock productivity and health

How do producers become certified under OSHP? Producers wishing to enroll in OSHP should contact the Ontario Sheep Marketing Agency (OSMA) for an application form Producers are required to pay $75 to OSMA for materials and administration for the first year and $42 for subsequent years After receiving the materials, producers quantify past flock productivity and set goals for future improvement. Their veterinarian then visits the farm to review relevant management practices, including disease control, bio-security, and quality assurance.

If the all requirements of the program are met the veterinarian will approve the producer for certification. The process is repeated yearly.

If you are interested in participating in this program please contact OSMA: Phone: 519-836-0043, email: projects@ontariosheep.org, Fax: 519-836-2531

Maedi-Visna Flock Status Pilot Project (MVFSPP) Maedi-visna is a debilitating viral disease that can undermine the economic viability of a sheep flock. The name Maedi-Visna is an Icelandic description of the two major forms of the disease (Maedi=progressive pneumonia and Visna=wasting). Although it is ultimately fatal, most of the economic loss attributed to this disease is due to decreased milk production; lowered weaning weights; increased incidence of severe arthritis and wasting; higher than average number of respiratory infections; and decreased ewe fertility. In one study, it was found that 66% of healthy appearing, Maedi-Visna positive ewes had udder lesions and their lambs had lower than average weaning weights. The disease is common in many sheep producing countries, and 70% of flocks tested in Ontario in the late 1980’s had at least one positive animal. There is no cure or treatment for the disease, however, there is a reliable blood test that can identify infected animals.

The Maedi-Visna Flock Status Pilot Project is a voluntary program administered by the Ontario Sheep Marketing Agency, in conjunction with the University of Guelph and the Canadian Food Inspection Agency.

The goals of the program are: 1. To identify and control the disease in participating flocks 2. To establish the economic costs and benefits of eradicating the disease Producers are able to establish a ‘whole flock’ status (all adult animals are tested) or a ‘monitored’ status (a representative group of adults are sampled). Producers are required to uniquely identify adult sheep, follow bio-security requirements, and complete the Ontario Farm Analysis Project. Although it is recommended, enrolment in the OSHP is not required.

If you are interested in finding out more about the Maedi-Visna project, please contact the OSMA office at (519) 836-0043 or email general@ontariosheep.org.

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Animal Disease Factsheets www.cfsph.iastate.edu This factsheet is made available by: The Center for Food Security and Public Health Iowa State University College of Veterinary Medicine The mission of the CFSPH is to increase national and international preparedness for accidental or intentional introduction of disease agents that threaten food production or public health.

Other resources at www.cfsph.iastate.edu • Handbook for Zoonotic Diseases of Companion Animals • Emerging and Exotic Diseases of Animals Book • Avian Influenza Resources • Wall Charts and Handouts

Published in IVIS with the permission of the Center for Food Security & Public Health, Iowa State University.

Maedi–Visna Ovine Progressive Pneumonia, Marsh’s Progressive Pneumonia, Montana Progressive Pneumonia, Chronic Progressive Pneumonia, Zwoegersiekte,La bouhite, Graff-Reinet Disease Content Update: March 19, 2007 Last Reviewed: July 5, 2007

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Importance Maedi-visna is an economically important viral disease of sheep that occasionally affects goats. The maedi-visna virus (MVV), a lentivirus; infects its hosts for life.

Although most infections are subclinical, a minority of animals develops progressive, untreatable disease syndromes including dyspnea (maedi) or neurologic signs (visna).

Both maedi and visna are eventually fatal. Additional economic costs may include marketing and export restrictions, premature culling, and losses from poor milk production due to indurative mastitis. Economic losses can vary considerably between flocks.

MVV is closely related to the caprine arthritis encephalitis virus (CAEV), a lentivirus found most often in goats. Although documented cases of natural cross-species transmission are currently rare, MVV can infect goats and CAEV can infect sheep. In addition, recombination has recently been demonstrated between MVV and CAEV. These findings suggest that eradication programs for either maedi-visna or caprine arthritis and encephalitis should now address both infections simultaneously.

Etiology Maedi-visna results from infection by the maedi-visna virus, a member of the genus Lentivirus in the family Retroviridae (subfamily Orthoretrovirinae). This virus becomes integrated into leukocyte DNA; infected animals become chronic carriers.

Several genetically distinct isolates circulate in sheep.

Phylogenetic analyses have demonstrated that maedi-visna virus is closely related to caprine arthritis encephalitis virus (CAEV), a lentivirus found most often in goats.

These two viruses share many features, and are often considered together as the small ruminant lentiviruses (SRLV). Early phylogenetic studies suggested that SRLV can be divided into six sequence clades, I to VI. Clade I contains the prototype Icelandic visna virus and related MVV strains. Clade II consists of North American lentivirus strains isolated from sheep. Clade III consists of Norwegian SRLV, and clade IV of French SRLV. Clade V contains French and Swiss CAEV strains, North American prototype strains, and North American ovine lentivirus strains. Clade VI contains French SRLV. In this analysis, clades III to VI contain related SLRV from both sheep and goats, while clades I and II are more species-specific. These findings suggested that these viruses might be more closely related to each other, in some cases, than to other CAEV or MVV, but they were based on short sequences of nucleic acids.

A new phylogenetic analysis, based on longer genetic sequences, divides these viruses into four principal sequence groups, A to D. Sequence groups A and B are divided further into subtypes. Group A contains at least seven subtypes and group B at least two subtypes. To date, subtypes A5 and A7, and groups C and D have been found only in goats. Subtypes A1 and A2 have been isolated only from sheep. Subtypes A3, A4, A6, B1 and B2 have been found in both species. Recombination between a group A maedi-visna virus and a group B caprine arthritis-encephalitis virus has recently been demonstrated in goats infected with both viruses.

Species Affected Maedi-visna affects sheep and, to a lesser extent, goats. Breed susceptibility varies.

Texel, Border Leicester, and Finnish Landrace sheep appear to be relatively susceptible to disease; Columbia, Rambouillet, and Suffolk sheep seem to be relatively resistant.

Serological evidence of SRLV infections has also been reported in wild ruminants including moufflin, ibex and chamois; however, preliminary evidence suggests that these viruses may be distinct from CAEV and MVV.

Geographic Distribution Maedi-visna has been found in most sheep-raising countries other than Australia and New Zealand. MVV has been reported from most of continental Europe, the United Kingdom, Canada, the United States, Peru, Kenya, South Africa, Israel, India, Myanmar and the southern regions of the former U.S.S.R.

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© 2007 CFSPH

Animal Disease Factsheets, The Center for Food Security & Public Health Iowa State University, Ames, IA, USA.

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Maedi窶天isna Post Mortem Lesions

Transmission Most animals become infected early in life, from drinking infected colostrum or milk. The virus can also be spread during close contact, probably by the respiratory route. Coinfection with pulmonary adenomatosis (Jaagsiekte) virus increases MVV titers in the respiratory tract, increasing contact transmission between sheep. Transmission has been reported from water contaminated with feces, but indirect spread is generally thought to be rare.

Intrauterine spread is thought to be negligible or minor.

MVV infects sheep or goats for life, but viral burdens vary between individual animals. Both asymptomatic and symptomatic animals can transmit this virus.

Sheep can be a source of SRLV transmission to goats, and vice versa. There is little information on the route(s) of transmission between sheep and goats, but the ingestion of contaminated colostrum or milk, or close contact between the two species in crowded barns have been suggested. Under experimental conditions, lambs that have nursed from infected goats can become persistently infected with SRLV.

Incubation Period The incubation period for maedi is usually more than two years; clinical signs typically develop when animals are three to four years old. The incubation period for visna is somewhat shorter, and symptoms can appear in sheep as young as two years.

Clinical Signs Most MVV infections are asymptomatic. In animals with clinical signs, the disease can take several forms.

Sheep with maedi, the most common form, experience wasting, progressive dyspnea and sometimes a dry cough.

Fever, bronchial exudates and depression are not usually seen. Maedi is eventually fatal; death results from anoxia or secondary bacterial pneumonia.

Visna occurs less frequently than maedi in sheep, although it is the more common form reported in goats.

Visna usually begins insidiously, with subtle neurologic signs such as hindlimb weakness, trembling of the lips or a head tilt, accompanied by loss of condition. The symptoms gradually progress to ataxia, incoordination, muscle tremors, paresis and paraplegia. Other neurological signs, including rare instance of blindness, may also be seen.

The clinical course can be as long as a year. Unattended animals usually die of inanition.

MVV can also cause slowly progressive arthritis with severe lameness, or chronic indurative mastitis with decreased production of normal-appearing milk. Weight gain in lambs may be decreased, possibly due to lower milk yields from dams with indurative mastitis.

Last Reviewed: July 2007

In maedi, the lungs are enlarged, abnormally firm and heavy, and fail to collapse when the thoracic cavity is opened. They are typically emphysematous and mottled or uniformly discolored, with pale gray or pale brown areas of consolidation. Mottling may not be obvious in the earliest stages of the disease. Nodules may be found around the smaller airways and blood vessels, and the mediastinal and tracheobronchial lymph nodes are usually enlarged and edematous. Secondary bacterial pneumonia may mask the primary lesions. On histological examination, lung lesions may include chronic, diffuse interstitial pneumonia, perivascular and peribronchial lymphoid hyperplasia, and hypertrophy of the smooth muscle throughout lungs.

Apart from wasting of the carcass, the only gross lesions seen in visna occur in the brain and spinal cord.

Focal, asymmetric, brownish pink areas may be found in the white matter of the brain and spinal cord, as well as on the ventricular surfaces. The meninges may be cloudy and the spinal cord may be swollen. On microscopic examination, the typical CNS lesion is meningoleukoencephalitis with secondary demyelination. In some cases, the inflammatory cell aggregates may be nodular or granulomatous, and necrotic centers may be noted in severe cases.

In ewes with indurative mastitis, the udder is diffusely indurated and the associated lymph nodes may be enlarged. Histologically, the udder is characterized by mononuclear infiltration of the periductular stroma; these cells obliterate the normal mammary tissue.

Arthritis may also be seen in some animals, and the kidneys may have microscopic evidence of vasculitis.

Morbidity and Mortality MVV is widespread among sheep in many parts of the world. In the United States, the prevalence varies with the region. Infection rates in sheep are highest in the Western and Midwestern States, and can reach nearly 50% in some areas. Control programs have reduced the incidence of MVV in some countries. Maedi visna is uncommon in goats; clinical cases have mainly been reported as visna in adult dairy goats.

Most infections are asymptomatic, but once clinical signs appear, the disease is progressive and usually fatal.

When MVV is introduced into a new area, the mortality rate may reach 20-30%. The mortality rate is low in regions where maedi visna is endemic; annual losses rarely exceed 5% in a flock, even when nearly 100% of the flock is infected. Co-infection with Jaagsiekte virus, the retrovirus that causes ovine pulmonary adenocarcinoma, results in more severe symptoms and increased transmission.

Management practices can influence the prevalence of infection and, thus, the frequency of disease. Clinical signs are not usually seen in herds with a low prevalence of infection. Genetic factors, including the breed of the sheep, influence the outcome of infection.

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Maedi窶天isna Diagnosis Clinical Maedi-visna should be suspected in animals that are at least two years old and have a wasting disease with slowly progressive respiratory distress, neurologic signs, indurative mastitis or arthritis.

Differential diagnosis The differential diagnosis for maedi includes pulmonary adenomatosis, parasitic lung infections, and caseous lymphadenitis with lung involvement. In cases with neurologic symptoms, scrapie, listeriosis, rabies, louping ill, parasitic central nervous system (CNS) infections and space-occupying lesions of the CNS should also be considered. Caprine arthritis and encephalitis can also resemble maedi visna.

Laboratory tests Maedi visna may be diagnosed by nucleic acid detection techniques such as polymerase chain reaction (PCR) assays, Southern blotting and in situ hybridization. PCR tests are used in some laboratories for rapid diagnosis.

Maedi-visna can also be diagnosed using a combination of serology and clinical signs, together with histological examination of tissues when necessary. Agar gel immunodiffusion and enzyme-linked immunosorbent assays (ELISAs) are the most commonly used tests. Immunoblotting (Western blotting) is generally performed only in specialized laboratories, but may be valuable when sera give equivocal results in other tests. Radioimmunoprecipitation and radioimmunoassay are generally used only in research.

Seroconversion generally occurs months after infection. In general, serology is of greater value in screening flocks or other populations than in diagnosing this disease in individual animals. In adult sheep and goats, a positive result indicates that the animal is persistently infected with MVV but, because most infected animals do not become symptomatic, it does not confirm that the symptoms are caused by this virus. Due to these limitations, serology is of greater value in screening flocks than diagnosing this disease in individual animals.

In seropositive, symptomatic animals, histology can confirm the diagnosis in biopsy or necropsy samples. Virus isolation can also be useful; however, viral titers are variable and may fluctuate over time. MVV is isolated by coculturing peripheral blood or milk leukocytes from live animals with sheep choroid plexus cells, sheep skin fibroblasts or other appropriate cell lines. MVV can also be isolated from tissues at necropsy. In co-cultures that display cytopathic effects, the presence of the virus is confirmed with immunolabelling methods and electron microscopy.

Adherent macrophage cultures established from postmortem bronchoalveolar lavage can be tested for virus production by electron microscopy or a reverse transcrip-

Last Reviewed: July 2007

tase assay. They can also be co-cultured with indicator cells for virus isolation.

Samples to collect Serum should be collected for serology. Milk can also be tested for antibodies. Virus isolation can be conducted on peripheral blood or milk from live animals. At necropsy, MVV can be isolated from the lung, mediastinal lymph nodes and spleen of animals with maedi. In animals with suspected visna, a sample of the brain should be sent. Alveolar macrophages can also be collected from the lung at necropsy, by post-mortem bronchoalveolar lavage. Samples for virus isolation and alveolar macrophages should be as fresh as possible.

Samples for histology should include all affected tissues such as lung, mediastinal lymph nodes, brain, spinal cord, kidney and/or udder.

Treatment There is no specific treatment for maedi visna. Supportive therapy may be helpful in individual animals, but it cannot stop the progression of disease.

Recommended actions if maedi-visna is suspected Notification of authorities Maedi-visna is a reportable disease in many states.

State guidelines should be consulted for more specific information.

Federal: Area Veterinarians in Charge (AVIC): http://www.aphis.usda.gov/vs/area_offices.htm State Veterinarians: http://www.aphis.usda.gov/vs/sregs/official.html

Control Maedi-visna is a contagious disease. Management practices can influence the prevalence of infection and, thus, the frequency of disease. Clinical signs are not usually seen in herds with a low prevalence of infection.

MVV is often introduced into a herd in live animals.

Additions to uninfected herds should come from MVVnegative herds. Other animals should be quarantined and tested before adding them to the herd. Uninfected herds should also be kept from contact with untested or seropositive herds, as horizontal transfer of the virus contributes to transmission. Goats may also be able to transmit SRLV to sheep. No vaccines are currently available.

MVV can be eradicated from a flock, or reduced in prevalence, by isolating lambs permanently from seropositive dams immediately at birth. The lambs are raised on uninfected colostrum and pasteurized milk, milk replacer or milk from seronegative ewes. The flock should also be tested frequently for MVV, and seronegative and seropositive sheep should be maintained separately. Ei-

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Animal Disease Factsheets, The Center for Food Security & Public Health Iowa State University, Ames, IA, USA.

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Maedi–Visna ther of these two techniques may be used alone for controlling maedi visna, but they are most effective in combination. Seropositive sheep should eventually be culled.

In nationwide eradication programs, quarantines of infected herds aid the final stages of the program.

Maedi-visna virus cannot survive for more than a few days in the environment, particularly under hot, dry conditions. Lentiviruses can be destroyed with most common disinfectants including lipid solvents, periodate, phenolic disinfectants, formaldehyde and low pH (pH < 4.2). Phenolic or quaternary ammonium compounds have been recommended for the disinfection of equipment shared between seropositive and seronegative sheep.

Public Health There is no serologic or clinical evidence that humans are susceptible to MVV

Internet Resources Manual for the Recognition of Exotic Diseases of Livestock http://www.spc.int/rahs/ The Merck Veterinary Manual http://www.merckvetmanual.com/mvm/index.jsp World Organization for Animal Health (OIE) http://www.oie.int OIE Manual of Standards http://www.oie.int/eng/normes/mmanual/a_summry.htm OIE International Animal Health Code http://www.oie.int/eng/normes/mcode/A_summry.htm

References Animal Health Australia. The National Animal Health Information System (NAHIS). Maedi-visna [online].

Available at: http://www. aahc.com.au/nahis/disease/ dislist.asp.* Accessed 15 Oct 2001.

Cutlip RC, DeMartini J, Ross G, Snowder G. Ovine progressive pneumonia [online]. American Sheep Industry Association; 2000 Feb. Available at: http://www.sheepusa.org/ resources/diseases/shopp.html.* Accessed 15 Oct 2001.

De Andres D, Klein D, Watt NJ, Berriatua E, Torsteinsdottir S, Blacklaws BA, Harkiss GD. Diagnostic tests for small ruminant lentiviruses. Vet Microbiol. 2005;107:49-62.

Gjerset B, Storset AK, Rimstad E. Genetic diversity of small-ruminant lentiviruses: characterization of Norwegian isolates of caprine arthritis encephalitis virus. J Gen Virol. 2006;87:573-580.

International Committee on Taxonomy of Viruses [ICTV].

Universal virus database, version 4. 00.061.1.06.008.

Visna/maedi virus [online]. ICTV; 2006. Available at: http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB. Accessed 15 Mar 2007.

Last Reviewed: July 2007

Timoney JF, Gillespie JH, Scott FW, Barlough JE. Hagan and Bruner's microbiology and infectious diseases of domestic animals. 8th ed. Ithaca, NY:Comstock Publishing Associates; 1988. Maedi-visna; p 871-872.

Kahn CM, Line S, editors. The Merck veterinary manual [online]. Whitehouse Station, NJ: Merck and Co; 2003.

Progressive pneumonia. Available at: http://www.merckvetmanual.com/mvm/index.jsp?cfile=h tm/bc/121505.htm. Accessed 9 Mar 2007.

Karr B M, Chebloune Y, Leung K, Narayan O. Genetic characterization of two phenotypically distinct North American ovine lentiviruses and their possible origin from caprine arthritis-encephalitis virus. Virology.

1996;225:1-10.

Peterhans E, Greenland T, Badiola J, Harkiss G, Bertoni G, Amorena B, Eliaszewicz M, Juste RA, Krassnig R, Lafont JP, Lenihan P, Petursson G, Pritchard G, Thorley J, Vitu C, Mornex JF, Pepin M. Routes of transmission and consequences of small ruminant lentiviruses (SRLVs) infection and eradication schemes. Vet Res. 2004;35:257-274.

Pisoni G, Bertoni G, Puricelli M, Maccalli M, Moroni P. Demonstration of co-infection with and recombination of caprine arthritis-encephalitis virus and maedi-visna virus in naturally infected goats. J Virol. 2007 Mar 7; [Epub ahead of print] Pisoni G, Quasso A, Moroni P. Phylogenetic analysis of small-ruminant lentivirus subtype B1 in mixed flocks: evidence for natural transmission from goats to sheep.

Virology. 2005;339:147-152.

Rolland M, Mooney J, Valas S, Perrin G, Mamoun RZ. Characterisation of an Irish caprine lentivirus strain – SRLV phylogeny revisited. Virus Res. 2002;.85:29-39.

Shah C, Huder JB, Boni J, Schonmann M, Muhlherr J, Lutz H, Schupbach J. Direct evidence for natural transmission of small-ruminant lentiviruses of subtype A4 from goats to sheep and vice versa. Virol. 2004;78:7518-522.

Smith M, Sherman D. Goat medicine. Pennsylvania: Lea and Febiger; 1994. Maedi visna and caprine arthritis encephalits; p. 135-138.

MacLachlan NJ, Stott JL. Visna/maedi/ progressive pneumonia viruses and caprine arthritis encephalitis virus. In: Walker RL, Hirsh DC, MacLachlan NJ, editors. Veterinary microbiology. 2nd edition. Ames, IA: Blackwell Publishing; 2004. p 421-422.

World Organization for Animal Health [OIE]. Manual of diagnostic tests and vaccines [online]. Paris: OIE; 2004.

Caprine arthritis/encephalitis and maedi-visna. Available at: http://www.oie.int/eng/normes/mmanual/ A_00071.htm. Accessed 9 Mar 2007.

Zanoni RG. Phylogenetic analysis of small ruminant lentiviruses. J Gen Virol. 1998;79:1951-1961. *Link defunct as of 2007

© 2007 CFSPH

Animal Disease Factsheets, The Center for Food Security & Public Health Iowa State University, Ames, IA, USA.

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Shepherd’s Calendar of Events The following summary provides an overall picture of when different management practices will occur throughout a reproductive cycle. Although it does provide the basics, it will not fit every operation and should be expanded or modified to accommodate the management priorities of each sheep farm.

Before Breeding Season Ewes • • • • •

• • •

Check udders for evidence of previous mastitis and/or Maedi-Visna (hard lumps etc.), and that both teats look functional Check mouths for missing teeth or other problems Check ewe production and age records Cull ewes that are not sound or have lower productivity than desirable, and replace with ewe lambs Flush ewes: - 1 pound grain/day or move to lush pasture 2-3 weeks before breeding (increases plane of nutrition increases fertility and ovulation rate) - If ewes are overconditioned, the effect of flushing will be lessened.

If necessary, vaccinate ewes for vibriosis and enzootic abortion (EAE) 2-3 weeks before breeding May wish to deworm at this time as well Replace any lost tags

Rams • • • • •

•

Evaluate sire production records. Cull and replace any rams with lower than desired productivity.

Check for general health and condition.

Check scrotal area (testis and epididymis) for any unusual lumps (Brucellosis) May wish to tested for sperm quality (not commonly done) Rams will spend a decreased amount of time resting and feeding at the beginning of the breeding season, therefore, for approximately 1-2 months before breeding season ensure rams are provided a good maintenance or flushing ration depending on their body condition. The plane of nutrition before breeding season will also have an effect on fertility, as sperm development takes ~50 days in rams.

Replace any lost tags

Breeding • The ovulation rates in ewes tend to be lower at the first part of the breeding season.

Running vasectomized or teaser ram with ewes for a few weeks early in the season tends to increase fertility and synchronize their estrous cycles (more condensed lambing).

• Allow at least 1 mature ram or 2 ram lambs per 50 ewes.

• Use a ram marking harness or painted brisket to monitor breeding. Changed colours (from lighter to darker shades every 17 days).

• Typical breeding seasons span ~2-3 estrous (34 to 51 days). You may wish to allow ewe lambs an extra cycle longer than normal (68 days). Remove rams at the end of the season.

Early Pregnancy (First 15 Weeks) • Feed according to body condition (put thin ewes into a separate pen and provide extra feed) • Mature ewes do not need a very high plane of nutrition at this point of pregnancy. Feed a maintenance diet of clean, but lower quality hay.

• Ewe lambs are still growing and should receive good quality roughages and grain (about 20 percent of the ration) during this period.

• If you vaccinate for abortion diseases, ewe lambs and new ewes in the flock should receive their second shot during mid-gestation.

Six Weeks Before Lambing • Increase energy in diet gradually to prevent pregnancy toxemia. An example of a feeding schedule is: o ~6 weeks before lambing, feed 1/4 to 3/4 pound grain/ewe/day o ~2 weeks before lambing 1 pound per ewe per day • Shear or crutch ewes before lambing. Control ticks and lice immediately after shearing.

• May wish to treat for internal parasites and trim feet at this time as well.

• Vaccinate ewes for Clostridial diseases (including tetanus).

• If white muscle is a problem in your area, feed selenium-vitamin E OR use an injectable solution • Check facilities and equipment to be sure everything is ready for lambing, this includes making provisions for additional help for doing night checks etc.

Lambing • Although average gestation is 148 days, the first lambs generally appear 142 days after turning the rams in with the ewes.

• Most lambs are lost just after birth and extra effort at lambing pays off with more lambs at weaning time. Be prepared to do checks through the night as well as during the day.

• Put ewe and lambs in lambing pen after lambing (not before).

• Grain feeding the ewes during the first three days after lambing is not necessary • Most ewes will lamb without incident. It is best to monitor their progress, but not to handle them or get too close unless it looks like she may be having problems. Learn the signs of a ewe in trouble (typical time for each stage of labour etc.) and know the basics of how to assist if necessary.

• Disinfect lamb's navel with iodine as soon as possible after birth.

• Be sure both teats are functioning and that the lambs nurse and are looking ‘happy’ • Some ewes may be able to nurse more than 2 lambs successfully; however, you may want to remove extra lambs. These lambs may be bottle fed or fostered to ewes with single lambs.

• Castrate and tail dock lambs before 1 week of age. Vaccine with sore mouth vaccine if it has been a problem in the past. Ear tag or otherwise identify the lamb(s). If the ewes were NOT given Se:E supplement during pregnancy, inject lambs soon after birth.

• If all is well, turn ewe and lambs out of the lambing pen after ~3 days • House ewes with single and multiple lamb separately and feed according to requirements (ewes with multiple lambs require more energy to maintain lactation) • Deworm ewes to prevent postpartum rise in worms

Lambing to Weaning • Feed ewes according to number of lambs.

• Provide creep feed for lambs (especially those born during the winter and early spring).

• Vaccinate lambs for overeating disease (Type D Clostridia) at five weeks and seven weeks of age.

Weaning • Lambs should be weaned between 50 and 60 days of age or when they weigh at least 40 pounds and are eating creep and drinking water. (remove ewes from sight and sound of the lamb pens if possible, if lambs not eating creep may consider using a ‘teacher’ animal (older lamb or yearling replacement animal) • Vaccinate for Type D clostridia again, 2 weeks before putting lambs on finishing ration • Decrease ewes’ energy intake ~1 week prior to and for ~2 weeks after weaning (feed low quality forage and remove grain). This helps decrease milk production and lessens the chance of mastitis.

• Handle the ewes as little as possible for about 10 days following weaning, to protect their udders until milk production has decreased.

Weaning to Pre-Breeding • If ewes go to pasture, treat for internal parasites.

• Feed a maintenance ration to the ewes.

• Don't over condition ewes prior to breeding.

Others Disorder Sore Mouth (Orf, Contagious Ecthyma)

Navel Infection

Joint Ill

Entropion

What do you See? • 8-10 days after exposure, small red spots appear which become small blisters • blisters break and form scabs after 3-4 days • common areas of infection are nose, eyelids, feet, and udder • young lambs have difficulty sucking and ewe may resist nursing if udder is sore • weaned lambs and adults may have difficulty eating and show lameness depending on affected areas • may have few initial signs • if severe, depression, high fever, weakness, lack of appetite, and death can occur quickly, if not treated promptly.

• commonly gives rise to joint ill • infection of one or more joints of the legs of lambs.

• stiffness, pain when getting up or walking • there may or may not be enlargement of joints depending on the type of causative organism • affected lambs become rough, gaunt, unthrifty and develop into runts • joints may ‘fuse’ preventing lamb from standing • inward turning of eye lid • excessive tearing and matting of wool on face • cloudy or ulcerated eye • eyes remain close and seem painfully • blindness can result if not corrected

Cause • virus, spread by direct contact between sheep via equipment • more susceptible if there are small cuts on the lips or gums present • cross contamination between ewe’s udder and lamb’s mouth is common

Treatment • self curing for weaned lambs and adults • nursing lambs should be monitored to ensure they are not becoming dehydrated (depressed, hollow-sided) • antibiotic creams have little affect since the causative agent is a virus Sore mouth is contagious to humans – wear gloves when handling infected animals

Prevention • a vaccine is available for flocks that have a serious problem with sore mouth (See vaccines page 135) • wear gloves when vaccinating

• infection of the navel cord at birth and extension into belly.

• antibiotics given daily for several days

• maintain sanitary lambing facilities • treat all navels with iodine or other disinfectant.

• bacteria may enter the body of the newborn lamb through the navel cord and localize in the joints • tail docking or castration wounds may also be bacteria entry sites

• acute cases can be treated with antibiotics • damage to joints will be permanent if treatment occurs too late

• as above • put lambs in clean grass pasture after docking or castration • sanitary lambing facilities and clean surgery important.

• severe cases are likely genetic • sometimes merely due to dried up birth fluids in wool, causing eyelid to invert • eyelashes rub against eyeball causing whitish discoloration • ulcerations of eye and blindness can occur if uncorrected.

• clear dried birth fluids from area surrounding eye • if it is a hereditary defect, fold out lower eyelid and apply wound clip, stitch to keep eyelid rolled out • eye ointment or pinkeye powder will help clear irritation once the underlying cause has been corrected

• breeding records may implicate a ram or ewe as being the genetic carrier

Regular De-worming Program Internal parasites can be a major problem for sheep in Ontario. Effective control of internal parasites will make a large difference in the productivity and profitability of your flock. These organisms cause a range of problems including decreased growth of lambs, poor reproductive performance of ewes, and can kill animals if left unchecked. Internal parasites of sheep include worms (e.g. roundworms, lungworms, etc.) and protozoa (e.g. coccidia) that live within the digestive and/or respiratory tract. Damage to the lining of the stomach and/or intestine can be severe enough to prevent nutrient absorption causing diarrhea and severe weight loss. Certain types of worms ingest blood, causing anaemia and weakening the animal.

Although there are a few notable exceptions, the life cycles of most internal parasites are somewhat similar. The adult organisms live and produce eggs in the stomach or intestines of the infected animal. The fertile eggs are passed with the manure and hatch outside the body. After a number of changes, a mobile infective larva is formed, attaches itself to vegetation, and may be eaten by a grazing sheep. The worm reaches sexual maturity after entering the stomach or intestine. The period from when the eggs are passed in the manure until the larvae have reached the infective stage is 3-4 weeks.

With repeated exposures, sheep do develop a natural resistance to parasite infections. This resistance is not as effective as the immunity developed against viruses and bacteria and does not kill the adult organisms.

However, the reproductive rate of the parasite is decreased, ultimately reducing the parasite load and the drain on the animal. Therefore, animals most susceptible to parasites are lambs (immature immune system and limited exposure) and animals with weak immune systems (disease, poor nutrition, other stresses). Even though adult animals will be relatively immune, if they are not managed properly they can contaminate the environment increasing the likelihood that vulnerable animals will be infected. Implementing a well-planned parasite management program is a very important aspect of your flock health program.

Chemical dewormers: Although there are a number of management practices that are important in controlling worms, most effective programs also involve the use of chemical dewormers. Using dewormers at times of the year and/or production cycle when sheep are most vulnerable to parasitism helps increase the effectiveness of treatment and reduce the overall use of chemicals. This will decrease costs and help to maintain the effectiveness of the chemical. (Note: protozoal infections are not treated using dewormers. Discuss treatment with your veterinarian).

One of the most important times to deworm is just after lambing, when there is a sudden release of infective eggs within the ewe's intestinal tract. Treating animals at this time minimizes the exposure of larva to newborn and young lambs.

Examples of deworming schedules are (Consult with your veterinarian and/or producers in your area for other suggestions): Ewes: Early lambing (January through February) • Deworming ewes shortly after lambing will help to protect young lambs.

• Deworm ewes again before they go to pasture to prevent pasture contamination.

• If possible, deworm flock again 3 weeks after the have been on pasture • Deworm ewes at weaning time Ewes: Late Lambing (April through May) • Deworm ewes in mid-winter (January, February) before the spring thaw, to prevent heavy contamination of pens or corrals during spring thaw • Deworm ewes shortly after lambing (before sheep go to pasture) and at weaning time Weaned lambs: • Deworm lambs at weaning time or before they enter feedlot or new pasture.

Replacements • Deworm all newly purchased stock when they arrive on farm at beginning of quarantine period and again 3 weeks later.

After deworming it is advisable keep animals in the same area for 12-24 hours, and then move them to a clean pasture or pen. Moving animals to a new pasture immediately after deworming will contaminate the pasture, as eggs will be passed with the dead worms. Animals will become re-infected sooner if they are put back into the original pasture.

Resistance to dewormers: Repeated use of the same dewormer can promote the development of strains of resistant parasites. This means that the dewormer will not be very effective and a large number of the worms will survive after treatment. These worms may pass their resistance to their offspring, creating a new line of resistant parasites.

Resistance to dewormers is a growing problem for the sheep industry and as dewormers lose their effectiveness, there are fears that economic losses from parasites will increase. In addition, there are concerns that certain types of these medications may be having a harmful effect on dung beetles (thought to naturally disperse and reduce worm eggs). Reducing the amount and the number of times medication is given will slow down the build up of resistant worms on the farm. The following strategies can help avoid this problem.

Fecal Egg Counts: Fecal egg counts (done by your vet) are important to determine the level and type of parasite infection. Fecal egg counts before and 10 days after the deworming also help ensure that the dewormer is effective. There should be a decrease of least 85 percent.

Rotating De-wormers: There are three main groups of wormers—benzimidazoles (e.g fenbenzadole); imidazothiazoles (e.g levamisole); and the avermectins (e.g ivermectin). Using a different family of wormer each year (for a full year) will help keep the parasite resistance down in your flock. Performing yearly fecal samples will help to determine if resistance to a particular group of dewormers is occurring.

Nutrition and Health Parasites are opportunists; as long as the animal is healthy and well cared for, the parasite load will be minimal. However, a poor immune response in stressed or malnourished animals will give parasites a chance to thrive. Animals in this situation are doubly affected, as they must fight the parasite infection as well as the original problem. A high parasite load is often a sign of other health problems, usually poor nutrition. Infected sheep provided good nutrition are, in some cases, able to reduce their worm load significantly.

Pasture Management: Many parasite larvae do not climb higher than a few centimetres from the ground. Since sheep are able to graze close to the ground, they are generally more susceptible to parasite infection than other livestock.

Good pasture management can help reduce parasite problems in grazing sheep. Allowing pastures to ‘rest’ for 6-12 months will help break the parasite lifecycle and clear the pasture of worms, if you have the land base and/or other species on your farm. Other effective methods are to graze hay fields, cropland, or grazing pastures with livestock not affected by sheep parasites (cattle and horses are good, not goats).

Although time between rotations may not be long enough to have a direct effect on larvae populations, rotational grazing programs may help reduce the effect of parasites by providing better nutrition. In addition, as mentioned earlier larvae do not crawl far from the ground, therefore it is important to prevent sheep from grazing the grass down too far. Pasture rotation will also help reduce the amount of fresh manure in the pasture. When possible, livestock avoid grazing near their own feces. As larvae will migrate only ~30cm from the manure, livestock will eat fewer larvae if stocking rates and rotation times are appropriate. Larvae

from most worms will die when exposed to dry conditions. Therefore, although overgrazing will increase parasite infections, allowing pastures to become overgrown isn’t the answer either, as the larvae population will increase if not exposed to direct sunlight. Maintaining grass at ~6 cm is ideal.

Harrowing fields aids in dispersing manure, as do dung beetles and earthworms in the soil, helping to dry and kill the larvae quickly.

Since lambs are the most susceptible to infection, manage your pasture rotations to minimize their exposure to parasites. Use a “clean” pasture (not grazed the previous year) if possible when lambing on pasture. If pasturing weaned lambs, move them to a clean pasture and allow ewes to graze the infested areas.

Sanitation For sheep in confinement housing, cleanliness is the best defence against parasites. To help minimize fecal contamination, use feeders that prevent animals from walking on feed or pulling feed onto the ground.

Locate waterers to prevent sheep from defecating in water and in areas with sufficient drainage. Pens, especially lamb pens, should be clean and dry.

Genetic Resistance Resistance to parasites has a strong genetic link, with certain sheep showing a greater resistance to infection than others. Being able to cull susceptible animals would be an ideal means of not only controlling parasitism, but also eliminating the problem completely. Unfortunately, an on-farm method of effectively and efficiently identifying susceptible sheep has not been developed.

Alternative Dewormers

There is little scientific evidence demonstrating that alternative dewormers (e.g. herbs, diatomaceous earth etc.) have positive effects on lamb growth and/or parasite load.

Summary

Parasites will thrive with: • mild winter • moist warm spring and summer • overgrazed or permanent pastures • marshy or wet pastures Sheep are vulnerable when: • very young or old • poor immune status (stressful conditions, poor nutrition, weather, overcrowding) • type and numbers of worms Preventing parasite infestation in sheep • strategic use of chemical dewormers • manage pasture rotations to avoid pasturing young animals on fields recently housing older sheep • avoid marshy or boggy pastures • prevent overstocking of pasture, but keep grass reasonably well grazed • break parasite life cycle (rest period, grazing with cattle etc.)

• maintain sanitary conditions in confinement housing • discuss parasite control with your vet

Common Internal Parasites Parasite Stomach Worms (Haemonchus)

Information/Lifecycle • attach to the stomach lining • suck blood and cause inflammation and ulceration

Signs • anaemia (pale mucus membranes) • swelling under jaw (bottle jaw) • sudden death may occur

Diagnosis • fecal exam • post mortem exam of dead sheep

Intestinal Round Worms

• cause damage to the intestinal lining

• enteritis, diarrhea, loss of appetite, loss of body condition, death • may be sudden deaths of fat ewes with large numbers of these worms present • rapid breathing, coughing, weakness

• as above

Lung Worms

Tapeworms

Sarcosporidiosis

Coccidiosis

• • • • •

more common in areas with wet, marshy pastures adults live in lungs eggs are coughed up, and swallowed into the digestive system larvae hatch and are passed with the manure sheep are infected after eating larva with grass

• as above • respiratory distress

• ‘sheep-type’ of tapeworms are common, since sheep develop an effective resistance to them, they not a great problem • ‘dog-type’ can be a problem for sheep as they form cysts in the muscles which may lead to condemnation of meat.

Regular (at least yearly, before pasturing sheep) deworming of dogs coming in contact with the flock is important

• not generally a problem to the health of the sheep, unless infestation is very heavy and interfers with normal bowel function (not normally seen in sheep over 1 yr)

• found in carcasses at slaughter

• protozoal parasite • cysts in esophagus, abdominal muscles, diaphragm, or cheek muscles causes condemnation of carcass • no treatment

• no obvious signs

• found in carcasses at slaughter

•

• consult with a veterinarian. Although this is a common cause of bloody diarrhea there are other diseases that may cause similar signs – correct diagnosis is important to minimize losses • fecal exam • for infected animals, anti-coccidial medication (not the same as dewormers) can be obtained from a vet • to prevent, provide prescribed daily levels of coccidiostat in ration (rumensin, decox) This type of medication requires a vet prescription for lambs

• • • • • • • •

often a major problem in young stock caused by a protozoa (coccidia) normally present in intestine and in soil sudden changes in diet and stress can cause coccidia to rapidly multiply and cause infection older animals become resistant to infections good feed management (locate feeders and waterers to avoid fecal contamination) locate pens on well drained land (coccidial organisms from the soil are less viable in dry conditions) good sanitation (lots of bedding) if pasturing lambs, avoid using pastures that recently housed older animals

common intestinal infection characterized by thin, watery diarrhea, often bloody • most often seen in feeder lambs, 23weeks after entering feedlot • during initial stages or if lamb is not severely affected, appetite may remain good, but growth and feed efficiency are affected • severely affected lambs go off feed, dehydrate, become weak, die

• fecal exam • may see worm segments (small white flecks) in manure or on hindquarters

External Parasites Parasite Sheep Ked

Lice (Sucking or Biting)

Blow Flies

Mange

Sheep Nasal Fly

Information/Lifecycle • wingless insect (6mm) • entire lifecycle (~4 months) on sheep • keds are most numerous in the fall and winter • spread with contact between sheep, worse with overcrowding • sucking lice feed on blood • biting lice sometimes feed on wool fibres, but more often on loose skin (scurf) and materials contaminating the wool • lice can live for a few days off their hosts • several species of flies commonly seen during the summer.

• flies lay eggs in open sores or on moist wool particularly around the hindquarters of sheep • after hatching the larvae feed on wool material, invade wounds and/or bore into the flesh of the sheep • mites

• fly related to the warble fly of cattle and bot fly of horses • prevalent in all parts of Canada (active during the summer) • deposits its larvae on or near the nostrils of sheep.

• larvae enter nasal passages and sinuses, irritating the membranes.

Signs/Diagnosis restlessnees and unthriftyness rubbing and loss of patches of wool adult keds are large enough to see heavily infested lambs may be stunted due to blood loss • decreased value of wool (rubbing) • decreased value of skins (blemishes from bites)

Treatment • shearing will remove many keds • discuss treatments with your vet (dust or spray insecticide) • apply treatments after shearing for best results.

Prevention • treat on regular basis after shearing • avoid overcrowding • prevent reinfestation by introducing only clean sheep into the flock.

• infested animals constantly rub against objects and scratch and bite themselves, so that their wool becomes dirty, ragged and torn.

• severe cases will interfere with feeding and resting.

• animals may be unthrifty and young sheep may be stunted in growth.

• lice spread rapidly in a flock • most infestations occur through direct contact and lice can be controlled best by treating infested animals.

• clean out bedding and spraying pens before returning animals • same treatment recommended for keds are effective against lice.

• treatment can be effective if carried out early (do regular pasture checks) • shear the animal, and the rest of the flock as soon as possible • remove as many maggots as possible by using benzene or chloroform • consult with your vet (5 per cent Korlan ointment may be affective)

• as above

• • • •

• affected sheep are normally away from the flock, lying down with their neck stretched out • affected sheep lose condition rapidly.

• maggots and smelly wool are obvious • sheep are “eaten alive” by burrowing larvae • absorbing toxins produced by maggots causes the sheep to die in a few days.

• intense itchiness (scratching, biting, rubbing, broken wool fibres) • scabs develop due to rubbing • severity and location of the scabs varies.

• itchiness may cause severe productivity decline • large amount of nasal discharge is present • discharge may interfere with breathing.

• sheep may push their nose into the ground or against other sheep to keep the flies away. This interferes with feeding and resting, preventing animal from thriving.

• in severe cases, nervous disorders may be seen and heavy losses may occur.

• shear sheep before fly season • sheep scouring from a lush pasture should be inspected often • tail dock lambs to prevent soiling • monitor docking, castration and shearing wounds during the fly season • as for lice and keds (avoid buying with new stock most important)

• none

•

infestations are less severe if sheep are given opportunities to escape from the fly (pastures with access to sheds or dense clumps of brush)

Regular Vaccination Program Sheep Vaccination The purpose of giving a vaccine is to sensitize an animal’s immune system to a specific bacteria or virus, without actually causing the disease. Under natural circumstances, a disease-causing pathogen (bacteria or virus) will enter the body, attack cells, and eventually cause the outward signs of the disease. The immune system will produce antibodies that are specifically designed to recognize and control the pathogen. If the animal survives the pathogen attack, its immune system will retain a ‘memory’ of that particular organism and will be able to respond more rapidly if it is encountered again. The strength of the immunity and length of time that it lasts depends on the type of pathogen and the overall health of the animal (i.e. poor nutrition and other stresses weaken the immune system). Manufactured vaccines mimic the effects of natural infection by exposing the immune system to controlled amounts of a disabled pathogen. The immune system reacts as it would to the disease, but the animal does not become ill. To maintain a high level of immunity, vaccines need to be given to sheep at regular intervals. If directly exposed to a disease-causing pathogen, even a vaccinated animal may show signs of the disease. However, the severity of the attack should be reduced, as the immune system will able to respond quickly to the pathogen.

Vaccines designed to mimic viruses may contain live viruses (modified to not cause disease) or killed viruses. Bacterial vaccines contain inactivated bacterial cultures (bacterin) or non-toxic derivations of bacterial toxins (toxoids). Antitoxins are available to reduce the effects of some bacterial diseases in unvaccinated animals (i.e. antitoxin for tetanus may be given if the animal receives a deep puncture wound, etc.).

Before using vaccines, read the manufacturer’s label carefully for information regarding administration and dosage recommendations for animals of different ages. Some vaccines are packaged in two parts; a dry component and a liquid component. The vaccine must be reconstituted (liquid portion mixed with dry) before administration. The product label will have instructions detailing the reconstitution and storage of the vaccine (e.g. refrigerate, expiry date). Vaccines that are not stored properly or are used after the expiration date may not provide the proper level of immunity. Consult with a veterinarian if the information on the label is not clear or if sheep are not included in the species listed on the label.

Vaccines are most often administered by a subcutaneous injection. A lump will often form at the injection site as part of the normal reaction to the vaccine.

Some of the more common vaccines used for sheep are listed below.

If you are just starting your sheep operation, contact your veterinarian to help determine which vaccines are important for your area. The ‘vaccination schedules’ provided below are suggestions only. Always follow your veterinarian’s advice and/or label instructions for administration.

Common vaccines for sheep: Vaccine Clostridial (bacterin or toxoid)

AND Caseous Lymphadenitis

Comments There are a number of diseases caused by Clostridial bacteria. These bacteria are naturally present in the environment (soil) or in the digestive tract. Clostridial vaccines are generally given in a combination vaccinations (3-, 6-, 7-, or 8-way vaccine); 8-way combinations include tetanus toxoid; 3-way and 6-way shots, may include caseous lymphadenitis.

Ewes

Lambs

Tetanus antitoxin (different from the vaccine) may be given if an animal has been wounded or is otherwise at risk

Ewe lambs Vibro

• use only if vibro is a problem in your flock (diagnosed by a pathology lab) or if you purchase ewes from flocks with unknown status (always best to ask for records and history) • sheep and cattle vaccines are different

Ewes

Vaccination Schedule • ewes that have not been vaccinated previously should be injected at eight weeks and four weeks before lambing. A single yearly booster vaccination given four weeks before lambing is required thereafter.

• antibodies from the ewe are passed on to their lambs via colostrum and milk (maternal immunity) to help protect lambs from Clostridial diseases until they are four to six weeks old. This also helps ‘kick start’ the lamb’s immune system • maternal immunity from vaccinated ewes will decline when the lambs are approximately six weeks of age. Vaccinating before this age may interfere with development of the lamb’s immune system.

• lambs should be vaccinated around the time the maternal protection decreases (6 weeks or weaning) • if ewes are NOT vaccinated during late pregnancy, lambs should be vaccinated within the first few days of life and again 2-3 weeks after and at weaning.

• if lambs are going on a high energy finishing ration, they should be vaccinated for Type ‘D’ again at approximately two weeks before the diet change to help prevent ‘overeating disease’ • vaccinate bought lambs for Type ‘D’ at purchase and 3 weeks after.

• ewe lambs selected for future-breeding stock should be vaccinated twice at six weeks of age and at two weeks after weaning • if ewes that have been vaccinated annually, give a booster shot 2-3 weeks before breeding • ewe lambs (not vaccinated previously) should be vaccinated 2-3 weeks before breeding and given a booster at mid-pregnancy • if you are uncertain about the vaccination status of new ewes, vaccinated at purchase and follow ewe lamb schedule

Common vaccines for sheep: Vaccine Contagious Ecthyma (orf or sore mouth)

Foot Rot

Rabies Lamb pneumonia (PI-3)

Comments • live virus vaccine which can be contagious to people if not applied properly • vaccine comes with a ‘scratch’ applicator • light scratch (deep enough for the vaccine to enter the blood system) is made to skin on a wool-free area and vaccine is brushed on • vaccination does not provide 100% immunity if exposed to heavily infected sheep or environment • only use in flocks with a history - the vaccine may cause the disease in clean flocks • check after a week –the vaccinated area should be appear raised and white, and the surrounding area reddish • resulting scabs are infectious, if vaccinating ewes ensure that they are vaccinated well in advance of lambing (so that lambs do not come in contact with loosened scabs) • may be used in infected flocks in conjunction with other treatments • only use on the advice of your veterinarian if there is a rabies outbreak in your area • nasal spray vaccine • may help decrease incidence of pneumonia • if you have a high incidence of pneumonia in young lambs, it may be more effective to look for and revise problems with housing (ventilation, drafts, sanitation etc.)

Vaccination Schedule Ewes and/or young lambs

• if you vaccinate ewes, do so well in advance of lambing (2 months prior). Immunity is not transferred to the lamb, but, if the lamb catches the disease, the ewe’s udder will be protected.

• vaccinate ewes in an area of the body free of wool (e.g. inside ear etc.)

• lambs should be vaccinated when a few days old • vaccinate lambs on inner thigh

All

• subcutaneous, high on the neck • may be necessary to give for a few years before any effects are noted

Young lambs

• give shortly after birth

Respiratory Disorders Disorder Pneumonia

Shipping Fever

Maedi Visna

What do you See? • any animal under stress may develop pneumonia – weak lambs are the most susceptible • lambs become feverish (40 to 41ºC ;104 to 106ºF), stop suckling and/or go off feed, become listless, weak and gaunt • fast shallow breathing at first, followed later by laboured breathing (puffing of sides), discharge from the nose • in poor conditions there can be a high death losses in a short time.

• some affected lambs appear initially to respond to treatment but will show chronic signs (coughing, especially after moderate exercise and poor growth), that do not respond to antibiotics • post mortem: lung abscesses • following weaning, transport, auction sales and other stress factors.

• high fever, droopy ears, off feed, reluctant to walk, rapid shallow breathing, progressing to laboured, frothy open- mouth respiration • sudden deaths are common when septicemia (blood poisoning) occurs.

Cause • stressed lambs (cold/wet, underfed) in presence of a variety of bacteria and viruses normally found in environment (PI-3 virus, pasteurella bacteria) • stress factors such as sudden changes in temperature, drafty, poorly ventilated overcrowded conditions • sudden chill, starvation, exhaustion, allows the bacteria and viruses to invade the lungs.

Treatment • make sure of diagnosis before treatment is started • take dead lambs to a veterinary clinic or laboratory immediately to differentiate from other causes.

• treatment with antibiotic, as recommended by veterinarian.

Prevention • keep lambing area clean and dry • ventilation of lamb barn is very important. If pneumonia is a persistent problem consider contacting an agricultural engineer or government specialist to assess barn • avoid stress and overcrowding of lambs • vaccine may be helpful in some cases

• variety of viruses and bacteria that are normally present in the respiratory tract take advantage of lowered resistance of lambs causing pneumonia.

• separate healthy from sick lambs • treat sick lambs with antibiotics (consult a veterinarian) • drench or stomach tube to prevent dehydrated lambs.

• slowly progressing of sheep usually seen after 3 years of age • some infected animals never show symptoms, but can infect others • gradually increasing respiratory distress, loss of body weight and death. (occasionally neurological) • decreased milk production due to ‘hard-bag’ mastitis of both sides of udder (decreased lamb growth)

• virus, spreads primarily from ewes to their lambs through colostrum and milk • also spread from sheep to sheep by direct contact (respiration) • possibly through blood • healthy seeming, infected sheep can spread the virus

• none

• avoid excessive stress at weaning • delay deworming, castration, vaccination until about ten days after shipping • introduce lambs to feed gradually provide good housing, dry bedding and avoid overcrowding • try not to mix lambs of various sources too quickly after arrival • using medicated feeds during stress periods may help (consult with vet) Active Prevention - Contact your veterinarian or OSMA for details on the Maedi-Visna testing program - Blood sample flock and cull positive animals - Maintain tight biosecurity to prevent reintroduction Passive Prevention: cull all sheep showing signs of progressive respiratory disease

The Risk to Sheep from Dog Tapeworms Dr. Paula Menzies, Dept Population Medicine and Dr. Andrew Peregrine, Dept Pathobiology, Ontario Veterinary College, University of Guelph Dogs and sheep naturally go together. Dogs are used to herd the sheep or guard them from predators and many flocks own at least one of these useful animals. Other canids such as coyotes, wolves and foxes commonly leave near sheep pastures. But without proper precautions, any of these canids can be a source of a parasitic disease that can rob your sheep enterprise of all its profits.

Canids can be a host to may different intestinal parasites, some of which can cause them illness. However, one of these parasites – tapeworms – do not generally make the dog sick, but the intermediate stage of these worms cycles through sheep and unfortunately, the damage that these tapeworms do the sheep carcass can cause them to be condemned at slaughter.

To understand how this happens, we need to understand the life cycle of the dog tapeworm. Adult tapeworms reside in the small intestine of the dog or other canid and use a scolex or head to grasp onto the wall of the gut. The tapeworms reproduce by shedding segments of their body each one of which contains thousands of eggs. These segments are not only found in the dog’s stool but can be seen “crawling” on its coat before finally dropping off. They look like a strange white, flat worm. When dried, these segments look like a grain of rice. The eggs are spilled out of the segment and can survive in the environment for up to a year - waiting for an opportunity to infect its next host - the sheep.

If these segments contaminate the pasture or forages that sheep are eating, the eggs will hatch in the sheep’s gut and the tiny larvae will burrow through the wall of the intestine to travel to its “target” tissue, where it turns into a small bladder-like structure called a cyst. Each one of these cysts contains an embryonic “baby” form of the tapeworm. If a dog or coyote gets an opportunity to eat the tissues that contain these cysts, this larval tapeworm will turn into an adult in the dog’s intestine and the cycle will continue.

Here in Ontario, there are two main types of dog tapeworms to worry about and they have different target organs in the sheep.

1. Taenia hydatigenia is the name of the most common tapeworm in the dog and Cysticercus tenuicollis , also called the bladder worm of sheep, is the name of the intermediate “cyst”stage in the sheep. The larval parasite prefers migrating through the liver and then developing into cysts within the liver tissue. After several weeks, the cysts may die. At slaughter, the liver may show long, wiggly migration tracts caused by a recent infection, moderately large cysts containing an embryonic tapeworm, or small round scars from an old infection. Or if reinfection is ongoing – the liver may contain all three. Regardless of which stage is found, the liver is condemned as unfit for human consumption.

2. The next tapeworm is less common but reports of the parasite are increasing in Canada – often with great economic cost. Taenia ovis in the dog, it is called Cysticercus ovis in the sheep, sometimes also called the sheep measles worm. Its

preferred tissues are the muscles of the body, including heart, diaphragm and skeletal muscle or meat of the sheep. At slaughter, small white cysts can be seen through the muscle. If found, the entire carcass will be condemned as unfit for human consumption.

So how common are these infections? In Ontario, an audit of condemnations found that 5% of lamb livers are condemned because of evidence of tapeworm cysts. In other parts of Canada, there have been cases where up to 30 lambs from one farm have been condemned because of C. ovis cysts in the muscle. This is an economically important disease to the sheep industry.

While these two tapeworms are not infectious to humans (unlike the cattle tapeworm), there is a dog tape in Ontario Echinococcus granulosus, which can harm people. It more commonly has a wolf-moose cycle in northern Ontario â&#x20AC;&#x201C; but can also cycle through the dog and sheep. It is the cyst form that infects humans. Fortunately control of T. hydatigenia and T. ovis, will also control echinococcus infection in dogs.

What should be done? Once the lamb is infected, there is no treatment so it is very important that all farm dogs be routinely treated for tapeworms every 3 months, and as frequently as every month if cysts have been found in sheep. A special de-worming medicine is required to kill the adult tapes, and can only be purchased from a licensed veterinarian. The wormers sold in pet stores or feed stores will not kill tapeworms. At the same time, make sure that all dead stock is buried at least 2 ft deep or is appropriately composted so that no scavenging can occur by dogs or wild canids such as coyotes, wolves or foxes. If the tapeworms infect the wild canid population there is little chance of eliminating it. Unfortunately the cyst stage of the infection can also occur in deer.

Once the wild canid - deer cycle is established in your geographic region, control in pastured sheep becomes very, very difficult. If you have any questions at all whether your dogs are infected, contact your local veterinarian right away.

In summary to prevent infection of your sheep with dog tapeworms: 1.

Do not feed any of your dogs (working, guard or pet) any part of a dead sheep.

2.

Do not dispose of dead sheep where dogs or coyotes or foxes might have access to it.

3.

Talk to your flock veterinarian to get your dogs on a regular tapeworm treatment program.

4.

Any new dogs coming to your farm must be treated and held in isolation for at least 3 days before exposing to the sheep farm.

5.

Try to prevent your dog from defecating where it might contaminate sheep feed, pastures or water sources.

6.

Make yourself aware of causes of condemnation of lambs that are sent for slaughter.

Urinary Calculi By: Jillian Craig Urinary calculi also known as water belly primarily affects wethers but can also affect mature rams. Calculi or stones get trapped in the urinary tract and prevent the ram or wether from urinating. Male sheep on a low roughage, high grain diets are most susceptible. Concentrate diets high in phosphorous and magnesium or have a calcium-to-phosphorous imbalance are considered to be the major cause of this disease. Water high in minerals or an inadequate amount of water can also contribute to urinary calculi.

While the symptoms may vary, animals are usually restless and anxious. Sheep may have abdominal pain, distention and rupture of the urethra, urine dribbling, edema under the stomach and loss of appetite. The sheep will take on a â&#x20AC;&#x2DC;hunched-upâ&#x20AC;&#x2122; appearance and urine may be bloody.

Untreated animals will eventually die since the bladder bursts and urine is absorbed into the bloodstream.

Treatment depends on the location of the blockage. Snipping off the urethral process may all that is required or utilizing antispasmodics and tranquilizers may aid in dislodging calculi. In serious cases surgery or euthanasia may be recommended by a veterinarian.

In order to prevent the occurrence of urinary calculi sheep should be fed a 2:1 calcium-tophosphorous ratio. Phosphorus and magnesium should not be added to diets. Including more roughage in the diet will help excrete phosphate in the urine. When feeding cereal grains, it is important to include other feedstuffs and minerals in order to make a balanced ration. Adequate water and salt intake are essential to prevent urinary calculi. Ammonium chloride can also be utilized in the diet to reduce the formation of calculi.

Information provided by: Susan Schoenian from Maryland Small Ruminant Page, www.sheepandgoat.com/

Flock Health Record Date

Animal Id

Condition and/or signs

Treatment (type of medication: dose; injection site)

Medication Withdrawal Date

Comments

Ventilation Basics for Sheep By: Robert Chambers P. Eng., Engineer, Swine and Sheep, OMAFRA, Fergus (Ontario Sheep News, November / December 2005) As we are moving into cooler weather it is time to review the basics of ventilation to ensure that we get the maximum comfort, and by association, performance from our flock. The vast majority of flocks in Ontario have some sort of shelter for the winter months. Though sheep can tolerate the cold given a proper diet, freezing, and near freezing rain combined with wind can be very detrimental to their health if they have no shelter to escape this type of weather.

Every type of structure used to house sheep, or any other animals, relies on ventilation to introduce fresh air and to remove excess moisture, dust, manure gases and to modify the temperature. Moisture and gases are produced by respiration and from the decomposition of the manure pack. Sheep produce two types of heat: sensible or dry heat and latent or heat from the evaporation of moisture (the animals breathe and the manure pack). Latent heat production tends to decrease as the air temperature goes down and sensible heat production goes up. The desired temperature is maintained in the barn by stocking density (more sheep, more heat until welfare is compromised), insulation (more insulation, less heat loss through the building shell) or additional heat (expensive). Fortunately for sheep producers, with the exception of very young stock, sheep are able to withstand a wide range of temperatures as long as they are in a dry and relatively draft free environment.

The goal is to have a Relative Humidity in the 50 to 75 % range; in this range condensation on the exterior surfaces is minimized and the animals are in their comfort zone.

This can be achieved by means of natural or mechanical systems that are designed to remove air from the building, but also control the incoming air as well. Humidity is removed from the barn by introducing outside air into the barn space, mixing it with the air in the space, and then exhausting it outside. One kg of outside air at -25°C for example can have a volume of 700 litres, a relative humidity of 100% and contains 0.4 grams of water vapour. The air enters the barn airspace and warms up to 15°C and the same kg of air has a volume of 820 litres, a relative humidity of 75% and contains 8 grams of water vapour. It then leaves the barn space via the exhaust system. Thereby, a kg of air at -25°C, 100% relative humidity can remove 7.6 g of water vapour from the airspace at 15°C and a relative humidity of 75%.

The type of shelter required depends on the production system. Those producers who lamb only in the early fall or late spring / summer can get by with only a rudimentary shelter, three walls and a roof with the open front to the South, is adequate. Whether it’s a non-insulated pole type structure, hoop barn or steel prefab type building the key to success is to orientate the opening away from the winter winds and towards the south. Animal comfort is reliant on a dry and relatively draft-free environment. The water system must be heated or insulated such to prevent

freezing and the barn temperature is allowed to swing in rhythm with the outside temperature.

Any attempt to seal these types of buildings to increase temperature results in very uncomfortable sheep and a rapid deterioration in the structure. It is a recommended practice to insulate under the roofing steel with 0.9 RSI or R5 in order to reduce condensation and to install chimneys or ridge vents. Hoop barns should have a ridge vent or chimneys to exhaust the warm moist air out the top, barring this, the tops of the end wall should be left open so as to allow the humidity to escape, through this technique will be less effective on longer barns.

For marketing reasons, many Ontario producers lamb year-round or through the winter, this entails a more complicated type of structure in terms of insulation and/or heating. Lambing pens should be kept about 2°C or greater with provisions of a means of heating sick/orphan pen(s) as the need requires. By placing claiming pens away from outside wall and/or drafts allows for greater comfort of newborns until they are dried off and adapted to their surroundings. In order to maintain a 2°C or greater temperature within the barn itself there is a need for heat and insulation. Heat can come in the form of the animals themselves and if required by the addition of a heater, typically a gas fired radiant tube heater. Insulation levels should be RSI 3.96 (R22.6) for the walls and RSI 5.32 (R30.4) for the ceiling. Again, supplemental heating may be required depending on production practices and the barn location (Lucan vs. Powassan for example).

Ventilation rates, either natural or mechanical should range between 1.75 l/s (3.7 cfm) per ewe minimum to 10.1 l/s (21.5 cfm) per ewe maximum. With proper stocking rates, ventilation can maintain a comfortable relative humidity and temperature while minimizing condensation on the exterior surfaces of the barn, through this assumes equal distribution in the barn. Many facilities have proper sizing of inlets and outlets (fans or chimneys), but have “dead pockets” of air that are detrimental to animal and building health. For these situations the addition of stir fans like those used in the poultry industry can aid in the proper distribution of air.

Wasting Diseases Disorder Johne’s Disease (Paratuberculosis)

What Do you See? • most often noticed in animals over 1yr of age • progressive weight loss to emaciation • may be diarrhea and soiling of fleece on hindquarters • poor lamb performance • affected animal dies after a period of illness

Maedi-Visna (see Respiratory diseases for details) Caseous Lymphadenitis (Pseudotuberculosis)

• some animals may be infected but not show signs, other than general wasting

Dental disease

Scrapie (See ‘Neurological Diseases for details)

• most often seen in animals over 6 months • signs depend on where disease manifests itself, may be no external signs but poor condition: external: lymph nodes of neck, under jaw, face, shoulder are enlarged, often abscess (open pus-filled sores) internal: abscesses form in lungs and other internal organs (respiratory distress) • general weight loss, poor production • sudden death may occur • most often in older sheep (3 yrs and older) • decreased appetite • weight loss • no signs of neurological disorders (not uncoordinated etc.)

• tooth loss, bad breath, poor gums • disease varies in signs, may see significant wasting before neurological signs – reportable disease

Cause/Transmission • intestinal damage due to bacterial infection, leading to inability to absorb nutrients • transferred by contact with infected animal (feces, colostrum, placenta) • bacteria can survive for 2yrs in environment

Treatment • none, cull suspected cases

Prevention • blood or fecal sample flock and cull positives (tests not always accurate) • maintain sanitary barn conditions • buy breeding stock from a known reputable source • consider testing a percentage of cull animals at diagnostic lab to determine incidence in flock (high incidence depopulation and restocking is an option).

Accuracy of test may be questionable – consult with your vet.

• bacteria enters through cuts and abrasions in skin • transmitted by direct contact between animals and contaminated shearing equipment • bacteria can survive for months in the environment

• culling of infected animals recommended • abscesses will heal, but reoccur

• very common disease, often spread by purchasing infected breeding stock • vaccine available; treat new stock before entering flock (often given in 3 or 6-way shot with closridial vaccines) • avoid cutting animals with shears, disinfect shears between animals • shear groups less likely to have the disease first (e.g. young animals before older animals)

• infection by various types of bacteria • cause unknown, maybe related to calcium:phosphorous imbalance in diet and/or excessively hard feeds (roots etc), possible genetic link

• none

• check Ca:P balance in diet • good quality feed • purchase young stock and check teeth before purchase • check for tooth loss in adults as part of pre-breeding check (with condition scoring and udder check)

Yew Poisoning in Sheep By: Dr. Jocelyn Jansen, Dr. Bob Wright and Todd Leuty Ontario Ministry of Agriculture Food & Rural Affairs The genus Taxus consists of three commonly grown ornamental shrubs: English yew (Taxus baccata); Canada yew (Taxus canadensis); and Japanese yew (Taxus cuspidata). The needles and seeds of all yews are highly poisonous to sheep and other livestock.

However, the red fleshy seed covering is not poisonous. Deer, moose and elk browse on yews as winter food and are not affected by the yew toxin.

Humans, particularly children, are also susceptible to the toxins in these plants.

The yew is known as the “tree of death”. Yew species contain a number of toxic alkaloids, the most toxic of which are taxine A and B. They are collectively referred to as ‘taxine.’ The toxin mainly affects the heart. Livestock are accidentally poisoned when yew trimmings are thrown onto manure piles, compost piles or over the fence where they are easily accessible to sheep and other livestock.

Yews are toxic all year round. Fresh and dried yew are both toxic. Consumption of as little as 110 g/kg of body weight for ruminants is lethal. This means that for a 150 lb ewe, 0.2 lbs to 1.5 lbs of yew is all that is needed to be fatal.

Clinical Signs Sudden death, often within two to three hours of ingestion, is the most common observation with yew poisoning. Animals are often found dead next to yew bushes or clippings. Other causes of sudden death in sheep include: copper poisoning, Clostridial diseases, botulism and bloat. Prior to death, muscle trembling, incoordination, nervousness, difficulty breathing, slow heart rate, diarrhea and convulsions may be observed. No post-mortem signs are specific to yew poisoning, unless partially digested twigs and needles are found in the mouth and stomach. There is no specific treatment or antidote for yew poisoning. Supportive therapies frequently have poor success rates and depend on the amount of yew ingested and how quickly actions are taken.

Identifying Yew Evergreens The native yew species include: the Canada yew a shrub found in eastern Canada; and the Western yew, a medium tree up to 20 metres high found on the west coast. Various yews are common as landscape ornamentals and include: the English yew, a tree/shrub that can grow up to 25 metres high, and the Japanese yew, a smaller shrub. Yews can withstand trimming and shaping and are easily transplanted. They can tolerate urban pollution but not road salt. All are poisonous to livestock, horses and humans.

Yews are evergreens, with flattened, somewhat curved, needle-like leaves. The leaves are 15 to 30 mm long with a prominent mid-vein. The upper surface is dark green with a paler green underside. The tip of the leaf is sharp. The edges appear to roll under. Leaves are spirally arranged as doubles, appearing to emerge from the stem on three sides. The bark is thin and scaly and varies from dark reddish brown to purplish brown. Yew seeds are hard, dark blue, about 8 mm long, and set inside a reddish, fleshy, cup-shaped, berry-like fruit. Seeds are found on the underside of recent twigs.

Evergreen branch clippings of yew are sometimes used to make Christmas ornaments, such as wreaths and hanging decorations.

Wreaths of yew should never be hung on barn doors or on fence posts where sheep or other livestock can reach them.

References Canadian Poisonous Plants Information System, http://www.cbif.gc.ca/pls/pp/poison Cornell University Poisonous Plants Information Database, http://www.ansci.cornell.edu/plants/yew.html Farrar JL. Trees in Canada. Markham, Ontario: Fitzhenry & Whiteside Limited, 1995. ISBN 155041-199-3 Knight AP, Walter RG. A Guide to Plant Poisoning of Animals in North America. Jackson, Wyoming: Teton New Media, 2001.

Dr. Jocelyn Jansen is a Disease Prevention Veterinarian, Cattle and Small Ruminants, with the Animal Health & Welfare Branch of the Ontario Ministry of Agriculture, Food and Rural Affairs, Wellington Place, R. R. # 1, Fergus, Ontario N1M 2W3