Animal Care

FANTASTIC BEASTS

Mark Newton-Clarke MAVetMB PhD MRCVS, Newton Clarke Veterinary Surgeons

It being another cold, bleak January, my thoughts wandered back to last November when Tracey and I were lucky enough to spend a fortnight in warmer climes. A friend who lives in Montserrat had invited us three years before but Covid delayed our first trip to the Caribbean. Surrounded by iguanas, agoutis and snakes, it wasn’t hard to find some inspiration for an article that would be read in the less-than-inspiring time that follows Christmas.

Exotic animal medicine and surgery is now a well-established speciality in the UK but years ago such expertise was limited and so many vets in small animal practice found themselves treating species quite unfamiliar to them. Nowadays expert advice is more available for owners as many more vets have undertaken further study in the exotics, allowing the rest of us to concentrate on what we know best.

Back in the day, I was working for a practice that served a safari park. The senior partner was often seen heading out to treat a giraffe or sea lion but I was never invited to join him on such important endeavours (actually to my relief). As a result of his expertise in exotics, we saw plenty of unusual creatures in the clinic and occasionally I became involved. One such day, a big male iguana was brought in – the owner had reported a sudden decline in mobility. After watching iguanas in Montserrat sunning themselves for hours without moving, I now wonder how the owner had noticed. Anyway, I was trying to figure out how to examine a very grumpy iguana without getting tail-whipped when Paul Heiney arrived along with a film crew! They were filming an episode of Countryfile at the safari park and decided to include some relevant veterinary footage. ‘Oh great – my day just couldn’t get better’ I thought as

Polina Bright/Shutterstock

I slipped on a white coat, tidied my hair (it was much shorter then) and tried to get into character as one of those TV vets who seem so comfortable being filmed while doing vetty things. Hoping that the practice principals had agreed some level of editorial control on the final cut, I tried to look confident in front of the camera and in response to Mr Heiney’s probing questions, recommended an x-ray. Looking back this was a stroke of good luck, as not only was it the right thing to do, as it turned out, it meant I could ban the entire film crew from the x-ray room and avoid further interrogation by Mr H. Oh how I blessed the Ionising Radiation Regulations that day.

Poor Iggy had a broken leg, obvious from the x-ray. What I also noted was the rather translucent appearance of all the bones – a clear sign of osteoporosis. So why would an iguana have brittle bones? Good question, Mr Heiney, who by now was in the x-ray viewing room alongside me and was clearly warming to his task of extracting as much information as possible out of an empty vessel. Now, all this was happening way before Dr Google was available and the senior partner was pulling a tooth out of a lion at the safari park. Playing for time, I telephoned the owner to report my findings and asked some questions about diet and the light source where Iggy spent his days. It transpired the UV light had broken some time before and had been replaced with a bulb that failed to emit the correct amount of UVB. Result: insufficient vitamin D production that led to deficient calcium absorption, forcing Iggy to draw on the calcium reserves in his bones which had just about become exhausted. The cause of the fracture was now clear, the crew declared it a ‘wrap’ and my career as a TV vet ended as quickly as it began.

So much for my iguana experience. There are no venomous snakes in Montserrat and so when a 4-foot, diamond-patterned snake was seen slithering across the lawn at our villa, I wasn’t as concerned as I would have been in the UK (adders have a zig-zag pattern down their backs). This beautiful creature was a Racer, which in other parts of the world snakes of the same name have been known to attack iguanas. In the Caribbean however, the Racer is from a different family and predates small rodents. My admiration of snakes was not shared by our friends so of course, it prompted me to share a short snakey story.

Several years ago, a vet student called Danny was spending some time at the clinic in Sherborne and staying in one of the upstairs flats. One day she invited me to meet her pet snake, Boa, which you can guess was a constrictor. Boa was very friendly and after we were introduced, started to wind herself around my arm. ‘Just relax,’ said Danny, ‘as if you become tense Boa will sense it and start to constrict.’ By this time, Boa’s 6-footlong body was starting to weigh down my arm and my fatigue must have been noticed. Clearly just wanting to distribute the weight more evenly, Boa decided to wrap around my neck…at which point my inner calm started to desert me. The inevitable response wasn’t long in coming as Boa went into constrictor mode, further increasing my tension. Luckily Danny came to the rescue and separated man and snake, much to my relief. That’s the last time I use a real Boa as one might use a feather boa! Not that I’m often seen with either. Happy New Year everyone.

LAME SHEEP

Jenny Gibson BVMSci MRCVS, Kingston Veterinary Group

Unfortunately, despite best efforts, many farmers end up with several lame sheep in their flocks. Lameness is easily spotted by ‘kneeling’ or ‘hopping’ sheep but is classified by any sheep unevenly weight-bearing, and even mild conditions can cause severe lameness. It is a welfare concern but also an expensive condition for the farmer due to its knock-on effects, such as reduced weight gain and reduced fertility.

The normal ovine foot consists of two claws with an interdigital space between them. There is a hard horn wall on the outside of each claw and a sole horn on the base of each claw which is softer and only 2-3mm thick which is easily penetrated. The wall horn grows at approximately 5mm a month and historically it used to be normal practice to regularly trim the whole flock. However, research has shown that this could be causing more issues and is therefore no longer recommended. Trimming is now only deemed necessary in very few cases.

There are several conditions that can cause lameness in sheep, the most common in the UK being ‘scald’ (commonly called ‘strip’) which is caused by the bacterium Dichelobacter nodosus. The bacteria gets in through damaged skin which is most commonly from rough pasture or very wet conditions which softens the skin. It causes inflammation between the claws with a white discharge. If a high proportion of the flock is affected, treatment through foot-bathing is recommended, whereas individual cases should be treated with antibiotic spray. Considerations for prevention need to be made, such as topping rough pasture and moving troughs regularly to prevent wet boggy areas.

Additionally, footrot and contagious ovine digital dermatitis (CODD) are very common causes of lameness in sheep. Footrot is a similar condition to scald as it is caused by the same bacteria but is more severe, as the wall horn separates away and becomes under-run and there is a foul odour. It is a very infectious condition and therefore prevention is key through vaccination, culling and careful selection of replacement ewes. Treatment involves antibiotic injection and spray and where possible, isolating those affected. CODD is caused by a different bacteria called treponemes. The infection starts at the coronary band as small ulcers and works down the toe and can cause

the horn to fall off completely. It can be quite hard to differentiate between CODD and footrot in some cases. Treatment with long-acting amoxicillin has been found to be most effective against CODD currently but prevention through quarantining and foot bathing should be the main priority. Less common causes of lameness in sheep include toe granulomas, toe abscesses, shelly hoof and trauma.

The target for farms in the past was to get lameness to under 5%, however, more recently some flocks are managing to aim for <2% lameness. Although, each farm is different and the first step for every farm is to work out the true lameness percentage on their farm currently and create an initial, reasonable, target based on the current lameness in the flock. To try and reach these targets farmers are using a five-point plan.

Cull - A forward culling policy is critical, especially in the first few years of trying to reduce lameness on farms. This is to reduce the spread of disease, remove chronic cases and try to improve the genetics on farms to build a flock with stronger/more resistant feet.

Avoid - Try to reduce the build-up of infection on pasture through grazing management. Using lime around handling areas or busy areas such as gateways or near water troughs reduces the spread of infection.

Treat - Rapid treatment is key – within 3 days of noticing lameness, they should be caught and treated but ideally as soon as possible. There should be a 3-strike policy in place on the farm so it is important to record all treatments so you know when the 3 strikes are up. Ideally, records should be kept as to the cause of the lameness and if unknown veterinary input should be sought.

Quarantine - Brought-in animals are high risk for introducing disease onto a farm so foot bathing new arrivals should be standard practice along with isolation from the rest of the flock for a minimum of 28 days.

Vaccinate - There is a licensed vaccine for footrot against the bacterium Dichelobacter nodosus. However, it only covers some strains of the bacteria, therefore, it is important to know what strains are on the farm to know if it will be of benefit.