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Sedate Kohler – 212 Final Story Horses are born competitors. Their long legs and muscled bodies are built to run long distances, whether from a predator, or an opposing army. However, the competitions that horses compete in now are more of a race than a marathon. And sometimes, sadly, they lose the race. Many of the equestrian sports that are popular now mimic the tasks done by horses in the past. For example, the sport of dressage is derived from the training of cavalry horses for war, and reining horses perform movements of the cowboys from the Wild West. However, the judging’s intensity has increased to the point that repeated competition and training can take a huge toll on a horse’s body. When a horse’s body breaks down, the first thing to go are the most important joints in the leg: the knee on the front legs and the hock on the hind legs. In order to diagnose and treat a horse with joint lameness, every veterinarian has a different protocol, and many also feel strongly about the process by which a horse is treated in order to limit the amount of secondary inflammation caused by the treatment. Unfortunately, these opinions vary widely. A veterinarian at the University of Wisconsin – Madison has done research to investigate the validity of these stigmas. Dr. Christine Wimer, DVM, MS, looked at the effects of several customary procedures performed by veterinarians on horses with joint injuries or weakness. When a veterinarian is called out to evaluate a lame horse, one of the first procedures done is a joint block. A veterinarian will regionally anesthetize the joint and then ask the horse to walk on the leg. If the lameness disappears, the horse is lame in that joint. If it isn’t, the horse is lame somewhere else lower in the leg. Once diagnosed, one solution is to inject various steroids and solutions into the joint with the hopes of improvement and recovery. When this treatment is performed, however, varies between each veterinarian. It is accepted among veterinarians that each needle poke into a joint increases the amount of inflammation and damage to the joint. Also, there is a possibility of a bloody tap, which means that when the needle goes into the joint, it punctures a blood vessel causing a small hemorrhage. Joint inflammation and the possibility of septic arthritis are serious complication of joint medication and treatment. As Dr. Wimer describes, “some veterinarians feel that they should space out the injection of the blocking solution and the medicine to fix the problem. Some tell their clients they’ll come back the next day, some the next 2 days, and some the next

Disjointed Diagnosis

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Does a needle poke really matter that much? If it's in a horse's joint, yes.

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Page 1: Disjointed Diagnosis

Sedate Kohler – 212 Final Story

Horses are born competitors. Their long legs and muscled bodies are built to run long distances, whether from a predator, or an opposing army. However, the competitions that horses compete in now are more of a race than a marathon. And sometimes, sadly, they lose the race.

Many of the equestrian sports that are popular now mimic the tasks done by horses in the past. For example, the sport of dressage is derived from the training of cavalry horses for war, and reining horses perform movements of the cowboys from the Wild West. However, the judging’s intensity has increased to the point that repeated competition and training can take a huge toll on a horse’s body.

When a horse’s body breaks down, the first thing to go are the most important joints in the leg: the knee on the front legs and the hock on the hind legs. In order to diagnose and treat a horse with joint lameness, every veterinarian has a different protocol, and many also feel strongly about the process by which a horse is treated in order to limit the amount of secondary inflammation caused by the treatment. Unfortunately, these opinions vary widely.

A veterinarian at the University of Wisconsin – Madison has done research to investigate the validity of these stigmas. Dr. Christine Wimer, DVM, MS, looked at the effects of several customary procedures performed by veterinarians on horses with joint injuries or weakness.

When a veterinarian is called out to evaluate a lame horse, one of the first procedures done is a joint block. A veterinarian will regionally anesthetize the joint and then ask the horse to walk on the leg. If the lameness disappears, the horse is lame in that joint. If it isn’t, the horse is lame somewhere else lower in the leg.

Once diagnosed, one solution is to inject various steroids and solutions into the joint with the hopes of improvement and recovery. When this treatment is performed, however, varies between each veterinarian.

It is accepted among veterinarians that each needle poke into a joint increases the amount of inflammation and damage to the joint. Also, there is a possibility of a bloody tap, which means that when the needle goes into the joint, it punctures a blood vessel causing a small hemorrhage. Joint inflammation and the possibility of septic arthritis are serious complication of joint medication and treatment.

As Dr. Wimer describes, “some veterinarians feel that they should space out the injection of the blocking solution and the medicine to fix the problem. Some tell their clients they’ll come back the next day, some the next 2 days, and some the next

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week. Every vet has a different protocol based on their previous experiences and cases.”

Wimer’s research aimed to sort out the differences in opinion between the amount of inflammation caused by simply putting a needle into a joint. In addition, they tried to figure out whether inflammation was caused by the procedure at hand, or the repeated needle poke in the horse’s leg.

With that knowledge, both veterinarians and clients will be better able to evaluate the situation and make better informed decisions about their horse’s welfare and treatment.

The research team included Dr. Wimer’s faculty advisor, Dr. Michael Livesey, Dr. Peter Muir, another professor in the Department of Surgical Sciences at the UW vet school, and Dr. Bettina Wagner, a professor of Equine Health at Cornell University, where Dr. Wimer received her DVM.

This world class team sought to investigate the extent and duration of the inflammatory process resulting from two common joint procedures: the placement of a needle into a joint and extraction of joint fluid, and a resulting in hemorrhage into the joint, and a joint lavage, which is where a joint is essentially washed with a solution, a common procedure for an infected joint. Lavaging is generally repeated every other day until the horse’s nucleated cell count and total protein of the joint fluid reach acceptable levels. Yet there again lies the issue of causing more inflammation and higher cell counts by lavaging the joint.

All of the horses used in the experiment were donated to the UW Vet Med Teaching Hospital for various reasons. One such horse Ferris, was an owner surrender.

For the months prior to his donation to the UWVMTH, Ferris was a normal 3 year old thoroughbred gelding. He was rambunctious and naughty to his owner sometimes. This led her to believe that he had some sort of lameness going on.

“Ferris’s owner brought him in and told me that he was lame. After doing a normal lameness exam on him, I told her that I didn’t think he was lame. She disagreed, and said that he had to be lame since he was bucking her off all the time. I told her he was 3. And 3 year old thoroughbreds have about as much maturity as a 10 year old human. They’re going to throw tantrums”, Dr. Wimer remarked. “I advised her to turn him out in a field for a year and let him grow up a little.”

The owner did not take her advice, and instead took him to every veterinary clinic in Wisconsin for a second, or rather multiple, opinion. Every clinic told her the same thing, that Ferris was not lame, except for one. This clinic diagnosed him with kissing spine, a defect in horses that causes the tops of the spinal vertebrae to start

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to lean towards each other and “kiss”. This results in serious inflammation and pain in the horse.

“After about 6 months of not hearing anything, we got a call from Ferris’s owner. She wanted him euthanized. Since the one clinic told her that he had kissing spine she didn’t want him anymore. So, we asked her if we could take him for research and she said yes.

As a horse in Wimer’s research project, Ferris first underwent an examination to ensure that he was not lame in any of his joints. His entire body was X-Rayed, and it was noted that his spine was not ‘kissing’.

Each horse underwent multiple trials of the joint procedures. The first was simply putting in a needle into the both the knee and hock joints and withdrawing two mL of synovial fluid. The horses were then bandaged and confined to a stall. A follow up sample is collected in the same way.

The procedure to evaluate the effects of a bloody tap included drawing 1mL of the horse’s own blood into a syringe and then injected into the joint once again.

Next, a needled was inserted into the joint and synovial fluid was collected. This joint was then lavaged, and 1L of Lactated Ringers solution was sent through. Another sample of the synovial fluid was collected like the first procedure.

To evaluate these samples for the amount of inflammation, Wimer submitted them to the Clinical Pathology service at the VMTH for cytologic evaluation. They examined the total protein, total nucleated cell count, and a cell type differential count. Each of these tests gave special insight to the amount and localization in inflammation in each joint, and are all the most current relevant markers of synovitis, or inflammation of a joint.

Their findings? No matter what, putting a needle in a horse’s joint causes inflammation. But that was accepted among all vets. Each procedure caused inflammation, but each for a different length of time.

Simple arthrocentis of both the carpal (knee) and tarsal (hock) joint caused a large increase in the inflammation after 6 hours, lasted for 24 hours, and was resolved 72 hours after the procedure.

Simulation of a bloody tap caused the biggest increase of inflammation by 6 hours, lasted for more than 24 hours, and resolved by 72 hours. This procedure resulted in a much larger increase in the total inflammation than the simple arthrocentisis.

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Finally, the lavaging of the joint cause another significant increase in inflammation by 6 hours. It was showing signs of resolving, but had not been completely resolved by 72 hours post procedure. The effect of this procedure was significantly greater than the simple drawing of blood.

Ultimately, the study shows that there is a serious inflammatory response in joints after procedures involving needles. All inflammation caused by the procedures was on its way to being resolved by 72 hours post-procedure.

Wimer’s research was a success. Not only did she clarify much of the confusion around injections into and from joints, but she also saved the life of a horse: Ferris.

Since completing his portion of the trials, Ferris found himself without a home. “We called the lady up after the research was done and asked her if she’d be willing for us to adopt him out. Again, she stated that she didn’t care what happened to him. “

With that being said, Dr. Wimer took it upon herself to adopt Ferris.

“I was the one that had radiographed his entire body: his skeleton was fine. He showed no signs of kissing spines. And I couldn’t let that go to waste! He helped me and now I needed to help him.”

Ferris is now living his life (and growing up as he does it) at a farm near Madison where Dr. Wimer keeps him. She hopes that he will grow up to become a great horse. She also hopes that he will never go through another joint injection again.