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The Lameness Issue
Casting Call
Managing distal limb injuries MRI additional tool for diagnosing lameness Technician Update: Preparing for the worst
Vol 6 Issue 8 2016
Table of Contents
Orthopedics
Casting Call for Distal
4 Limb Injuries
Cover photo: shutterstock/Joan Gomez Pons
diagnostics
MRI: Additional Tool for Diagnosing Lameness...............................................................11 News
Passion Becomes Practice............................................. 3 Research to Help Racehorses Put Best Foot Forward..........................................................10 How the Vikings Sent the Gaited Horse Around the World..............................................14 Mystery of Sable Island’s Growing Wild Horse Population....................................................15 Innate Immune System in Dental Disease..........19 Concerned About Donkeys?........................................19 Two Treatments to Reduce Inflammation...........19 advertisers Shanks Veterinary Equipment.................................. 3 Merck Animal Health.................................................. 5 Standlee Premium Western Forage......................... 7
Electric Hoof Knife....................................................... 8 Boehringer Ingelheim................................................ 9 AAEVT............................................................................15
The Modern
Equine Vet Sales: Matthew Todd • ModernEquineVet@gmail.com Editor: Marie Rosenthal • mrosenthal@percybo.com Art Director: Jennifer Barlow • jbarlow@percybo.com contributing writerS: Paul Basillo • Kathleen Ogle COPY EDITOR: Patty Wall Published by PO Box 935 • Morrisville, PA 19067 Marie Rosenthal and Jennifer Barlow, Publishers percybo media publishing
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News notes
Animal Planet takes viewers behind the scenes of the University of Pennsylvania School of Veterinary Medicine as six students embark on a journey to graduation. With unprecedented access to the school’s two internationally renowned teaching hospitals — New Bolton Center hospital for large animals and Ryan Hospital for companion animals — Life at Vet U gives an exclusive look at the grit and grind it takes to make it in this highly competitive world.
The six-part series premieres Saturday, Oct. 1 at 10 PM ET/PT. The six-part series premieres Saturday, Oct. 1 at 10 PM ET/PT. Penn Vet challenges its students with daily highstress, fast-paced situations and gives them the opportunity to receive rigorous training and feedback from some of the top pioneers in veterinary medicine. From the intricate work of cataract surgery to a stallion collection for artificial insemination, each student gets the hands-on experience her or she will need for a career in veterinary medicine. Penn Vet is equipped with some of the most advanced technology in the industry and sees nearly 40,000 patients a year. From dogs and cats, to horses, cows and zebras, the students are challenged constantly to be prepared for anything. As graduation approaches, the students brace themselves for the most important day of their career — Match Day. Do they get placed at their dream hospital, or do they have to scramble to even find a placement? From lifelong dreams of working with animals to the courageous decision to completely change a career path, Life at Vet U follows each student on the road to becoming a veterinarian. It is a personal journey, but the underlying drive for each of them is the same — a passion to improve the lives of animals.. MeV
Courtesy of Animal Planet/Discovery Channel
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Orthopedics A forelimb cast being applied; shows where the assistant holds the cannon bone so that the foot is in a neutral position; also the stockinette has been rolled down.
Casting Call for
Courtesy of Dr.. Janicek
Distal Limb Injuries The application of a foot cast in a horse with hoof wall avulsion, collateral ligament injury or even distal phalangeal fracture offers multiple advantages over a simple bandage. A good cast can decrease convalescence for the horse, and save time and labor costs for the B 4
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client, according to John Janicek, DVM, DACVS, of the Brazos Valley Equine Hospital in Salado, Texas. The definition of a foot cast can vary from farrier to farrier and from veterinarian to veterinarian, but Dr. Janicek explained that a good foot cast incorporates the
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sole, the entire foot and the hoof wall, and extends up to the proximal pastern just below the fetlock region. “These casts should be put on the distal limbs while the horse is standing whenever possible,” he said. “This enables the horse to re-
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Orthopedics
Courtesy of Dr. Janicek
A completed hind limb cast...minus the acrylic
A hind limb with the foot being positioned on a wooden block so that the caudal half of the foot extends from the block; stockinette has been applied, as has the orthopedic felt.
engage the normal hoof-pastern axis, and it allows the cast to conform to the foot quite nicely.”
Pre-Casting Consideration
Before casting, take radiographs, he recommended. “In Texas, we see a lot of wire and sheet metal lacerations,” Dr. Janicek said. “I think it is imperative that you take an x-ray of the foot to make sure there is no metallic foreign body in the limb.” If the veterinarian has the smallest reason to suspect wound communication to a synovial structure, then that should be evaluated as well. “The last thing you want to do is apply a cast on a horse with at septic joint, tendon sheath or navicular bursa.” For heel bulb or pastern lacerations, Dr. Janicek uses as small of a 6
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Do not wrinkle anything, including the cast material. Wrinkles can cause focal pressure in the region that will lead to a pressure sore. bandage as possible after addressing the initial wound. He’ll often remove the horse’s shoe and trim the foot to avoid having the shoe
A completed forelimb cast....minus the acrylic
penetrate the cast.
Forelimb
“With the front leg, I have an assistant hold the leg at the level of the distal cannon bone,” he said. “I want that leg to fall into as much of a neutral position as possible. That will also keep the stockinette held at a good tension.” After placing a 1-inch strip of orthopedic felt and securing it with a piece of tape along the two edges, Dr. Janicek will initially work proximal to distal. “When I start putting on the cast material, I will only cover half of the orthopedic felt while moving up and down the leg,” Dr. Janicek explained. “When I unroll it, I make sure to cover half of the tape each time around as well.”
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Orthopedics
The warmer the water, the faster the casting material will cure. It’s the same for the weather. The warmer the ambient temperature, the faster the cast will cure. The casting material should be applied snugly, but not extremely tight, and it should include the entire foot. After finishing the first roll, fold the stockinette down and incorporate it into the cast. For the last roll of casting material, Dr. Janicek will fan-fold it five or six times in 6-inch increments and place it on the solar surface of the foot. He will then wrap it around the toe and secure it to the rest to the foot. “Once I have the last piece of casting tape in place, I’ll set the horse’s foot on the ground and allow it to
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Issue 8/2016 | ModernEquineVet.com
cure,” he said. “This will allow the cast to set in a normal hoof-pastern axis.” After the cast is fully cured, Dr. Janicek will place a 50:50 dry mix-to-liquid ratio of acrylic in a non-styrofoam disposable cup. He will pour the acrylic on to a piece of aluminum foil, and wait until it becomes tacky. “Then I’ll pick the foot up and set it down on the aluminum,” he said. “I’ll wrap the foil around and try to spread the acrylic as smoothly as I can. Once it sets and becomes a little more firm, I’ll put the foot back down on a flat surface and take the rest of the foil off and add some elastic tape. I get a good, flat, conforming surface that will lead to fewer casting complications in the foot.”
Hind limb
Much of the forelimb materials and techniques will overlap in the hind limb, but the horse’s reciprocal apparatus requires a few changes. “It’s important to have the horse’s foot extend off the caudal edge of a foot block,” Dr. Janicek said. “Most of the cast is put on while the horse is in a weight-bearing position.” In the fan-folding portion of the cast wrapping, Dr. Janicek will have the technician hold the horse at about the level of the distal cannon bone. “You don’t want to lift the leg up,” he said. “You just want to pull the leg forward as much as you can. You don’t want to start to flex these joints because of that reciprocal apparatus. The cast will not fit well.” Secure the material to the foot with a figure 8, and once the last layer of cast material is in place the foot can be set down to allow the cast to cure in a neutral, weightbearing position. Apply some elastic tape, and let the cast cure some more. Acrylic can be applied afterward. Tell the client to be on the lookout for fluid, evidence of a break in the cast or pressure sores. If the horse becomes lame at any point, then an immediate examination and/or cast modification is indicated. “When you’re putting these casts on the distal limb, you can definitely decrease time and labor costs for the client when compared with bandaging,” Dr. Janicek said. “Casting can take two to three weeks, but bandaging can take six to eight, including multiple bandage changes. The cast may cost more initially, but the cast may be MeV cheaper overall.”
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news notes
Research to Help Racehorses Put Their Best Foot Forward An international research team is working to understand how shoes affect foot skeleton stress in racehorses, in a project that is likely to benefit the racing industry and protect horses from injury. Olga Panagiotopoulou, PhD, head of the Moving Morphology and Functional Mechanics Laboratory at University of Queensland School of Biomedical Sciences, in Brisbane, Australia, said that musculoskeletal injury is one of the main animal welfare concerns in the industry. The Australians, The Royal Veterinary College in the United Kingdom and Brown University in Providence, R.I., are harnessing a new approach that combines threedimensional (3D) radiographic technology with computer simulations and models of the forces exerted on bones. “This novel combination has enabled us to study the effect of a stainless steel horseshoe on skeletal stresses within the forefoot in a live racehorse,” Dr. Panagiotopoulou said. This is the first report of using this combination of techniques in horses. The method was used effectively in a preliminary case study at the Royal Veterinary College in London, but more research was need, according to Professor John Hutchinson, PhD, vertebrate biomechanics and evolutionary anatomy researcher at the college. The research involved walking a Thoroughbred between 3-D radiographs, an imaging technique developed by Professor Stephen Gatesy, PhD, and colleagues at Brown University in Rhode Island, and used previously to view bone interaction in small animals such as fish and birds. Dr. Panagiotopoulou used film industry animation techniques to transform the radiographic data into a lifesize 3-D model. “By combining the 3-D model with other research data we were able to measure the force the horse's foot bones generated when they hit the ground and develop comprehensive simulations,” she said. They hope this work will pave the way for new direc-
Film industry animation techniques transformed the radiographic data into a life-size 3-D model.
By combining the 3-D model with other research data they were able to measure the force the horse's foot bones generated when it hit the ground and develop comprehensive simulations.
tions in research that will minimize foot injuries and improve animal health and welfare. “Future research using more animals will enhance our understanding of what regions of the horses' feet are most at risk of damage,” she said. MeV
For more information: Panagiotopoulou O, Rankin JW, Gatesy SM, Hutchinson JR. A preliminary case study of the effect of shoe-wearing on the biomechanics of a horse’s foot. PeerJ 2016 4:e2164 https://doi.org/10.7717/peerj.2164 10
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Diagnostics
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Standing magnetic resonance imaging (MRI) is an additional tool for substantiating or disproving a provisional lameness—not a replacement for radiographs, history and examination, explained Stacey W. Kent, VMD, of Equigen LLC in Cochranville, Pa. Don’t be “discouraged or frustrated when you get results that are not as you expected or that may in some cases require you to do some additional blocking and workup,” she said at the 61st Annual Convention of the American Association of Equine Practitioners. “I think we often expect that MRI will be the key that unlocks the lameness mystery. While that’s often the case, there are other times when MRI results are just another piece of an already complex puzzle,” said Dr. Kent, whose practice centers around advanced diagnostic imaging. She presented several cases to show how she used MRI hand in hand with nerve blocks, radiographs and ultrasonography. Case one
A Thoroughbred gelding with a racing career presented with an acute right hind lameness. On initial evaluation with a nerve block, the lameness was localized to the distal rim. The radiographs suggested a fracture of the lateral
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plantar process of the distal phalanx. Three days after the initial radiographs were taken, the horse stopped bearing weight on the right hind limb, although when blocked, he could bear weight on the hand limb, but he was still lame on the trot, she said. He was referred for MRI, where a standard distal limb study was completed. “I’m a little bit of a control freak so I’m present for acquisition of all images at my clinic. This allows me to have the freedom to concentrate on some areas a bit more or if need be, to add additional areas,” she said. “So in this case, I dropped the magnet down to make sure I was getting adequate fat suppression in the distal phalanx and not missing any areas of bone edema, and then once I did not appreciate anything distally, I raised the magnet to look more proximally.” The MRI results showed an incomplete midline sagittal fracture in the proximal phalanx. Based on this information, the referring veterinarian took some additional radiographs, and the fracture lines were easily appreciated. “So in this case, the blocking pattern in radiographs steered the provisional diagnosis in one direction, and while that diagnosis was ultimately disproved, the information gathered from the MRI evaluation proved to be quite useful,” she said.
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Case one
Images courtesy of Dr. Kent
MRI:
Additional Tool for Diagnosing Lameness
Case one
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Images courtesy of Dr. Kent
Diagnostics
Case two
Case two
Case two
A Connemara gelding used for dressage was experiencing a lowgrade left front lameness for approximately a year. Because of the horse’s travel schedule, he had seen several veterinarians, who employed multiple treatments throughout the year to address the left-front lameness including intraarticular therapy of the distal interphalangeal joint, intra-articular therapy of the proximal interphalangeal joint, intra-articular therapy of the lower tarsal joints, regional limb perfusion with tildronate disodium and some corrective shoeing. “All of these therapies had varying results, some were more successful than others, but ultimately the horse still was chronically lame,” Dr. Kent explained. The horse was basically sound when trotted in hand, but 1/5 lame on the left front under tack when trotted to the left. The referring veterinarian also thought there was a little bit of right front lameness on a circle to the right. Anesthesia of the lateral and medial palmar digital nerves improved the left front lameness, but might 12
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Findings from the MRI often require further work up and tests. have made the right front lameness a little bit worse. “It wasn’t until a left front mid pastern ring block was used that the lameness in the left front was abolished,” she said. “So at this point, nothing else was done regarding the right front because the left front had sort of been the ongoing issue.” Radiographs of the front foot and fetlock were relatively unremarkable, but ultrasonography of the left front pastern indicated some mild abnormalities and enlargement of the proximal and lateral aspects of the left front straight distal sesamoidean ligament with subtle fiber disruption. An MRI was done to confirm the desmitis of the left front straight distal sesamoid and liga-
ment and to check for additional abnormalities. The MRI indicated some abnormalities associated with the navicular bone. “Remember, during the initial evaluation, palmar digital nerve anesthesia did improve the lameness, [but] we had to go up a little bit higher to completely abolish the lameness. In my opinion the findings that were identified in the front foot on this particular evaluation do tend to fairly consistently block out with the palmar digital nerve anesthesia. So with that in mind and also given the fact that I wanted to image the straight distal sesamoid and ligament, the magnet was raised to the level of the metacarpophalangeal joint,” she explained. Raising the magnet not only confirmed the ultrasound results, but also noted one of “the most significant findings on the study” a focal area of sclerosis in the distal media third metacarpal bone with mild enthesiophyte formation associated with the joint capsule attachment. This is the type of case that could be really frustrating for clients, who might not understand that MRI findings point to areas that might
Case 3
A Hanoverian gelding in training as a dressage prospect was noted to have an acute left front lameness, which a nerve block localized to the distal limb. Radiographs were unremarkable. The referring veterinarian discussed the possibility of returning to do some slightly more specific nerve blocking to further characterize the lameness and also discussed the possibility that an MRI might be needed to help diagnose this lameness, but the client declined further diagnostic work up. Instead, the owner turned to the internet and decided that her horse had a soft tissue injury because radiographs were unremarkable. “So she implemented
her own therapy program and after six weeks of box rest, she called me to set up a standing MRI for her horse, presumably to evaluate this presumptive soft tissue injury and see if the horse was ready to return to a work program,” Dr.. Kent said. “I called the referring veterinarian on the case to discuss this and she was actually quite surprised to hear that all of this had gone on because there had been no follow up since the initial evaluation.” The MRI found a complete short transverse fracture at the junction between the ossified collateral cartilage and the medial palmar process of the distal phalanx and identified no significant soft tissue abnormalities, according to Dr. Kent. Armed with the MRI information, Dr. Kent took radiographs but the fracture line could not readily be seen. “It was very easily hidden and it was only by playing around with my degree of obliquity that I was able to pick that up, so this [fracture] is one of those ones that is sort of very easy to be missed on a standard set of foot films,” she said. “So in this case, there really was not a provisional diagnosis to substantiate or disprove. I really included this case more as a cautionary tale for us to share with our clients about the pitfalls and perils associ-
Images courtesy of Dr. Kent
need more investigation, she said. To the client, the veterinarian has done nerve blocking, ultrasonography and MRI and that should be enough. But actually, the findings point to the need to “further tailor some of your blocking and perhaps start with some intra-articular anesthesia of the metacarpophalangeal joint, see what kind of a response you get to that and also consider intra-articular anesthesia of the distal interphalangeal joint or even intrathecal anesthesia of the navicular bursa,” Dr. Kent explained.
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ated with independent and internet research,” she said. While MRI is a very useful tool, [we should] explain to clients that findings identified on MRI evaluation may require further work up. “I think it’s safe to say that time and time again we’ve seen the absolute necessity and usefulness of standing MR imaging in diagnosing equine distal limb lameness. And I think if we continue to treat it as an additional tool in our diagnostic toolbox rather than expecting it to always answer all of our questions, we’ll be in good shape,” MeV she said.
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news notes
How the Vikings Sent the Gaited Horse Around the World
Credit: Monika Reissmann
Ambling horses are particularly prized for their ability to travel in a way that's comfortable for riders, with a smooth, four-beat rhythm. Earlier studies traced that easy gait to a single typo in a gene involved in coordinated limb movement. Now, researchers who have genetically examined historic horse remains said that gaitedness in horses made its first appearance in Medieval England around 850 AD and rapidly spread from there by Vikings who brought them to Iceland.
Ambling Iceland pony during World Championship.
“We detected the origin of ambling horses in medieval England,” said Arne Ludwig, PhD, of the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany. “Vikings took these horses and brought them to Iceland and bred them there. Later, ambling horses were distributed from England or Iceland all around the world.” Ancient DNA offers a window into the past. In the new study, the researchers assembled DNA samples, including 90 horses going back to pre-domestic times, before 3500 BC, through to the Middle Ages. They examined the DNA in search of that earlier identified “gait keeper” variant in a gene known as DMRT3. The researchers detected the telltale genetic change in two English horses from 850 to 900 AD and in 10 out of 13 individuals from Iceland dating to the ninth to eleventh century. The gait keeper variant was absent in all of the horse remains from mainland Europe. Dr. Ludwig and colleagues said that the discovery 14
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that ambling horses were present in Iceland so long ago strongly suggests that Norse people from Denmark and South Sweden took them from the British Isles to Iceland. “Considering the high frequency of the ambling allele in early Icelandic horses, we believe that Norse settlers selected for this comfortable mode of horse riding soon after arrival,” the researchers wrote. “The absence of the allele in samples from continental Europe (including Scandinavia) at this time implies that ambling horses may have spread from Iceland and maybe also the British Isles across the continent at a later date.” It is improbable that the English and Icelandic gaited horse populations developed independently from each other in such a short time. “It is much more likely, that the first horses ever imported to Iceland already carried the mutation for alternative gaits. The Vikings recognized the value of the gaited horses and preferentially selected for this trait, thereby laying the foundation for the worldwide distribution,” explained Dr. Ludwig, geneticist at the IZW. Dr. Ludwig said that they were a bit surprised that the gait keeper variant didn't arise sooner, mainly because the trait now occurs so widely in horses all around the world. But, he notes, with strong selection in the course of breeding domesticated animals, “everything can happen very fast.” Historic sagas also suggest that Icelandic horses exhibited the ability for alternative gaits at an early stage. Although the origin of the Icelandic horse is not fully resolved, the general assumption is that they came to the island together with the Vikings. However, since the mutation was not found in Scandinavian horses of the 9th century, horses from other regions must have been brought to Iceland as well. Historic records report that Vikings were repeatedly pillaging on the British Isles and conquered the region of today's Yorkshire — precisely the region from which the two historic gaited horses originated. “Taking that into account our results suggest that Vikings first encountered gaited horses on the British Isles and transported them to Iceland,” explains Saskia Wutke, PhD student at the IZW and first lead author of the study.
The high frequency of the mutation for gaitedness in the early Icelandic horses indicates that the Icelandic settlers preferably bred gaited horses — apparently the comfortable gaits proved to be particularly suitable for long distance travel through rough terrain.
There are still many open questions about how human preferences changed over time and how those shifts influenced horses. The researchers said they are also interested in how those past events continue to influence domesticated animals and animal breeding today. MeV
For more information: Wutke S, Andersson L, Benecke N, et al. The origin of ambling horses. Curr Biol. 2016 Aug 8;26(15):R697-9. doi: 10.1016/j.cub.2016.07.001 http://www.ncbi.nlm.nih.gov/pubmed/27505236
University of Saskatchewan (U of S) biologists have made a significant advance in understanding the ecology of Sable Island and its iconic wild horses — one that underscores how intimately connected living systems are. The number of Sable Island horses is at an historic high — now ranging from 450 to 550 horses compared with only 200 to 400 during the past 250 years. A team led by Philip McLoughlin, PhD, and Keith Hobson, PhD, has been trying to find out why the numbers have grown so much. Dr. McLoughlin, an associate professor in Biology at the U of S and his team demonstrated a link between burgeoning seal populations on Canada's east coast and the foraging habits of feral horses along the length of Sable Island. They found that grey seals, whose numbers on the island have swelled from fewer than 1,000 in the 1960s to nearly 400,000 currently, have their pups on the island and fertilize the sandy, wind-swept grasslands — transferring nutrients from the sea that promotes growth of the grasses where feral horses have now chosen to feed. Dr. McLoughlin cautioned that more research is needed to say definitively whether the increase in seal numbers is increasing the survival and reproduction of the horses feeding near seal colonies. But measurements prove the seals do enrich the island's plant growth with nitrogen from feeding on fish in ocean, and computer modeling has demonstrated that the horses preferentially select those particular grassy areas to eat.
Credit: University of Saskatchewan
Mystery of Sable Island’s Growing Wild Horse Population
“What is really interesting is that we show how the enrichment of grasses, which occurs non-uniformly on the island, then affects how the horses move around the island to eat,” he said. “This speaks to the question of how seemingly distinct systems — ocean and land — can be interconnected by fundamental ecological relationships.” The team's next step is to determine whether nitrogen originating from the sea is detectable in the tissues or hair of the horses and to the extent it explains their reproduction and survival. The project was funded by the Natural Sciences and Engineering Research Council and the Canada Foundation for Innovation, with in-kind support from Parks Canada Agency and Fisheries and Oceans Canada. MeV
Sable Island's growing wild horse population.
For more information: McLoughlin PD, Lysak K, Debeffe L. Density-dependent resource selection by a terrestrial herbivore in response to sea-to-land nutrient transfer by seals Ecology. 2016;97(8):1929. http://onlinelibrary.wiley.com/doi/10.1002/ecy.1451/full ModernEquineVet.com | Issue 8/2016
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technician update
Importance of Preparation in an Emergency By Brandi Larsen, CVT On a cold January afternoon, the day was like any other….until the phone rang. A client on the other end of the line was hysterical and the only information we could get was that “a horse is bleeding from head to toe and will be arriving to the clinic in 5 minutes.” The clinic was short staffed that day with myself and one other technician available for appointments and walk-in clients and one doctor. Prior to the arrival of the patient, it was my responsibility to prepare for a polytraumatic laceration patient with no further details to help me. I began gathering supplies and preparing for the worst. I quickly gathered an IV catheter, blood tubes, hypertonic saline 7.2%, lactated Ringer’s solution, hetastarch 6%, bandage materials, tourniquets, laparotomy sponges, a sterile general laceration instrument pack, and aminocaproic acid since I was unaware of the severity of hemorrhage. The practice was fortunate enough to have blood donor horses available as needed in the face of severe hemorrhage and hypovolemia, which was also in the back of my mind. Following the setup of primary drugs and supplies, I set up the digital radiograph and the digital ultrasound machines to access quickly if needed. I then waited patiently near the parking lot for the next trailer to pull in, which would be the patient. On arrival, I notified the attending veterinarian that the patient had arrived and headed toward the trailer meeting the client at the trailer door and did my best to calm and reassure her that we would do everything we could but that we needed to assess the patient in the trailer first to avoid further trauma. I observed a steady projection of arterial blood coming from a severed metatarsal artery on the lateral aspect of the left hind metatarsus as well as a large volume of blood on the floor of the trailer. The patient had a large laceration to the head, distal to the fore-lock as well as several superficial abdominal lacerations. Three out of four limbs displayed dropped fetlocks indicating possible tendon and ligament involvement as well as possible articular lacerations. I immediately and safely applied a simple pressure bandage to the left hind limb metatarsus to achieve hemostasis of the metatarsal artery until the veterinarian could assess the injuries further. I carefully led the patient off the trailer and into the clinic, attempting to minimize the risk of further trauma. 16
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The owner told me that he was an 8 year old, Quarter Horse gelding. Once the patient was safely in the clinic, I immediately performed a physical examination which revealed the patient was normothermic with a rectal temperature of 100.8° F. He was tachycardic with a heart rate of 100 beats per minute and tachypneic with a respiratory rate of 40 breaths per minute. He had no increase in respiratory effort and his lungs ausculted within normal limits with no wheezes or crackles appreciated. His heart rhythm was also within normal limits with no murmurs or arrhythmias ausculted and a normal sinus rhythm. Borborygmi was ausculted bilaterally in the abdomen in all four quadrants and found to be unremarkable. The patient had a clinically normal capillary refill time of less than 2 seconds and his mucous membranes were hyperemic and moist. I was unable to obtain an accurate analysis of his digital pulses due to the nature of his injuries. His mentation was anxious and stressed with no neurologic deficits immediately observed. He had severe polytraumatic acute lacerations to the head, abdomen and limbs. During the examination, the owner told us that she had found the patient in his daily turnout pasture in this condition. Around and next to him was the barb wire fence used throughout the property and it appeared he had attempted to run through it for an unknown reason, became tangled, struggled and ripped free of the barb wire. She also told us that she purchased him the previous November and that he is current on his vaccinations, including tetanus toxoid and had been recently dewormed. After I completed the physical examination, I obtained a blood sample and submitted it to the laboratory for a complete blood count (CBC), chemistry 12 panel, fibrinogen, lactate analysis and most importantly, a packed cell volume (PCV) and total protein (TP) analysis to assess hypovolemic status. As we waited for the results, I clipped and prepared a site aseptically for an IV catheter. I opted to forego the use of a sedative until we knew what the PCV and TP values would be to reduce any risks associated with hypovolemia. Using sterile technique, I placed the IV catheter and began to prepare for IV fluid therapy. Results from the blood work indicated normovolemia with a PVC of 40% with a total protein value of 5.5 g/dL and the lactate value as only slightly increased at 3.2 mmol/L. I was surprised at this value due to the amount of blood loss observed on the trailer in the pasture where the patient was
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• A three course, 10 module, equine-only online program offered through ACT • Geared toward Credentialed Veterinary Technicians, Assistants, Support staff, & Students • Areas of study include: equine medical terminology, anatomy and physiology, parasitology, laboratory, diagnostics, equine basics (breeds, wellness, husbandry,) diagnostic procedures, emergency medicine, restraint, pharmacology, surgical assistance and anesthesia, equine office procedures • A certificate of completion is awarded to those who: Successfully complete required courses Complete the list of required skills (per a supervising DVM who is an AAEP member) Attend an AAEVT regional CE symposium and participate in the we labs • Those individuals who successfully complete the programs will be recognized as AAEVT Certified Equine Veterinary Technicians / AAEVT Certified Equine Veterinary Assistants depending on their current designation. The certificate is recognized by the AAEVT and the AAEP but does not grant the credentialed status by the AVMA • For more information go to www.aaevt.4act.com or call 800-357-3182
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Fo r m o re i n f o r m a t ion v ist w w w.a ae vt.or g
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*American Association of Equine Veterinary Technicians and Assistants
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technician update
Skills a veterinary technician needs during an emergency include emergency set-up, advanced pharmacology practice and full preparation for severe trauma with limited information in a very short time. found. When assessing blood loss, the patient had approximately 32.13 to 36.72 L of blood and could withstand approximately a 30% loss (9.64 to11.02 L) before a blood transfusion is warranted. This can be difficult to estimate which is why it is important to achieve hemostasis as quickly as possible on arrival, note the amount of blood loss observed in the trailer, and obtain blood work results quickly. The CBC and chemistry panel were unremarkable with only a mild increase in blood glucose (145.4 mg/dL), GGT (61.1 U/L), CK (981.5 U/L), and AST (657.1 U/L) most likely due to struggling and stress from the injuries. Following interpretation of the blood work, the veterinarian ordered a sedative to lower the stress factor, provide some analgesic effect, and safely restrain the patient to investigate the injuries closer. I administered xylazine and butorphanol IV. Following sedation, I got the digital radiology machine to assess the damage and determine if the lacerations communicate with any articular spaces. The attending veterinarian placed a medial and lateral abaxial nerve block bilaterally in the forelimbs in order to explore the wounds and determine the severity of the trauma. I opened a general instrument pack then applied a humane twitch to the patient for restraint during the wound exploration. Using a teat cannula, the veterinarian was able to measure the depth of the laceration. With the teat cannula in place, another technician positioned the radiology plate for a lateral view of the foot, pastern and fetlock, which displayed a clear image of the teat cannula communicating with the coffin joint. In the view, a metal barb from the fence was lodged in the lateral aspect of the coffin joint that must have broken off while the patient struggled to free himself from the fence. The teat can18
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nula was removed and the wound was explored digitally with the veterinarian able to palpate the coffin joint space and the navicular bursa. To be complete, an arthrocentesis of the right forelimb coffin joint was also performed. Another technician performed an aseptic preparation of the right forelimb coffin joint to prepare for the arthrocentesis. Using sterile technique, the veterinarian inserted a needle into the coffin joint and used a syringe to aspirate synovial fluid unsuccessfully. He then used several other needles placed in different areas of the coffin joint and used a syringe filled with sterile saline to inject into the coffin joint to see if the joint would hold the pressure. Unfortunately, the saline aspirated from the wound in all three attempts. The right forelimb was the most severe in terms of trauma due to articular involvement and contamination, however further complicating a good prognosis was the dropping of the fetlocks bilaterally in the hind limbs. The veterinarian asked the client if this was his normal conformational presentation which she declined indicating suspect tendon and ligament trauma. Based on the findings on the right forelimb, the client and veterinarian consulted about all possible scenarios including the possibility of spending a great deal of money, only to be unsuccessful with treatment. Due to the prognosis, the client opted for the difficult choice of euthanasia. The veterinarian informed her that this was not a wrong decision based on the findings of only the right forelimb and not including the severity of the injuries to the other limbs, abdomen and head. Although this was not an ongoing complex case involving surgery or extended hospitalization, it was a good example of the skills a veterinary technician needs during an emergency, which include emergency set-up, advanced pharmacology practice and full preparation for severe trauma with limited information in a very short period of time. Even though the veterinarian did not use the majority of what I prepared prior to the patient’s arrival, making a plan prior to a trauma helps your team work together more efficiently, eliminates stress, and allows patients to receive needed treatment faster. MeV
About the author
randi Larsen, CVT, is an independent consultant B in Weatherford, Texas. She has piloted and implemented custom veterinary training programs in large animal practices in Texas as well as lent her knowledge as a speaker at veterinary conferences nationwide.
News notes
Innate Immune System in Dental Disease
Two Treatments to Reduce Inflammation Healthy cartilage functions much like a sponge, absorbing synovial fluid during joint movement. The daily activities of horses in training produce wear and tear on the joint, which results in synovial membrane and joint capsule inflammation that dehydrates the articular cartilage, creating more damage, which leads to more inflammation in a self-perpetuating cycle. Repeated bouts of inflammation leads to loss of cartilage and the permanent bony changes that are hallmarks of osteoarthritis. Merial offers hyaluronate sodium (Legend) and firocoxib (Equioxx) to help control joint pain. Legend is proven to safely and effectively treat noninfectious synovitis associated with equine OA. It reduces joint inflammation as well as clinical and subclinical synovitis. Equioxx, a non-steroidal anti-inflammatory drug (NSAID), provides relief of equine inflammation in just one daily dose. For competitions, EQUIOXX is the only NSAID approved for use up to 14 consecutive days by both the American Quarter Horse Association (AQHA) and the UnitMeV ed State Equestrian Federation (USEF).
The expression of mRNA encoding for all cytokines was increased in tissues affected by periodontitis compared with healthy controls, with IL-12 showing the greatest increase. Within the same horse, diseased tissue sections again showed increased cytokine expression compared with tissue from healthy sites. MeV
For more information: Kennedy R., Lappin D., Dixon PM, et al. Toll-like receptor and cytokine messenger RNA levels in equine periodontitis and oral health. Equine Vet J. 1216 July 12. [Epub ahead of print). http://onlinelibrary.wiley.com/doi/10.1111/evj.12597/full
Concerned About Donkeys? How are donkeys different from horses? Why do they seem so stubborn? Whether you are a veterinarian, a veterinary technician or just a fan of equids, the Donkey Welfare Symposium held Sept. 30-Oct. 2 at the Cornell College of Veterinary Medicine in New York is an opportunity to learn about the medical and nutritional needs of this sturdy little equid. Other sessions will focus on the continuing importance of donkeys to economic success in developing countries. Highlights include: • Demonstrations of donkey handling, training and shoeing • Lectures on donkey behavior and veterinary needs • An adoption event featuring donkeys from a rescue organization • Remarks by a retired Marine colonel about Smoke, a donkey that MeV helped boost morale among troops in wartime Iraq Registration is required. For more information, visit donkeywelfaresymposium.com.
Shutterstock/Geza Farkas
Toll-like receptors and cytokines of the innate immune system are increased in gingival tissue affected by periodontitis, suggesting recognition of pathogenic bacteria by Toll-like receptors results in receptor upregulation and in turn, increased expression of proinflammatory and anti-inflammatory cytokines. Researchers compared concentrations of several Toll-like receptors and cytokines of the innate immune system in gingival samples from 13 healthy horses and 20 with signs of periodontal disease to tease out the role of innate immunity in periodontal disease. They found a significant correlation between the severity of periodontal disease and the expression of TLR2, IL-1, IL-6, IL-10, IL-12p40, IL-17 and TNF-. The expression of mRNA for TLR2, TLR4 and TLR9 was significantly increased in tissue samples from the periodontitis group compared with the healthy gingivae group. In particular, TLR2 mRNA showed a very large increase (389-fold) compared with controls. In some subjects, the researchers also compared samples of healthy gingival tissue with diseased lesions within the same horse, with mRNA expression for these TLR again being increased in diseased sections.
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