Page 95 - July 2015

Wobbler syndrome refers to horses that shows neurologic signs, especially related to the spinal cord, EPM, EHV-1 or vitamin E deficiency.
Wobbler disease refers to horses that have compression of the spinal cord, which can be caused by things such as injury, congenital malformation, tumors, arthritic vertebrae, etc.
“It doesn’t really matter whether it’s pinching or infection, lack of vitamin E or
lack of myelin—an important part of the cell membrane—you end up with the same kind
of signs in the horse. It’s easy to take blood samples and check these things at the same time a neurologic and lameness exam is being done. Now, with many practitioners having good digital radiography equipment enabling them to get good films out in the field, they can radiograph the neck and possibly see where a problem might be originating. If clinical signs are such and there are radiographic changes, then a myelogram is indicated to see if there is cord compression or not,” he says.
“The myelogram puts a contrast agent around the cord. With an iodine compound that outlines the spinal cord, you can see whether or not there is pressure being placed on certain areas. You take radiographs in a neutral position, where the horse’s neck would be when just walking around. Then, you flex the neck and see if there’s one area that ends up being more compressed when you change the position and angle of the neck,” says Grant.
“If you have a positive myelogram, then you must decide whether to go ahead with surgical
Radiographs of the neck,
as well as neurologic tests, can help diagnosis and help the patient in the long run.
treatment. Some younger horses, under a year of age, might respond to drastic changes in diet (that does not allow them to grow so fast) so the bones around the cord might not become so large so quickly. In my experience, however, if you don’t start these changes in diet very early (before a year of age), you don’t have very good luck.” You’d have to diagnose the problem early and know what was going on with the horse, and the younger the better.
The most frustrating cases are the ones with only subtle changes. The owner may think the young horse is just gangly and going through
an awkward or clumsy stage. “There are many things you can do to monitor the growth of young horses without having to enlist the help
of a veterinarian. If you check the horse every
2 months, watching him back up and do tight circles both directions, do placement tests, watch the horse walk up and down hills, etc., you can start picking up any subtle changes early on,” says Grant. He suggests recording these exams on a digital camera or smart phone. Then, the images can be used later for comparison or sent to someone for a second opinion.
“If you are worried about the horse or if he seems to be getting worse, you can have your veterinarian do a neurologic exam and take blood samples and radiographs. Then, you can make a decision early about possible treatment, rather than put it off,” he says.
A myelogram puts a contrast agent around the spinal cord and can give a definitive diagnosis by showing a malformation of the cervical vertebra, which can make a horse wobbly due to cord compression.
“Many times, with the economy the way it is, people don’t want to spend money on the horse or they think the problem will go away by itself. But sometimes you need a fresh set
of eyes to look at the horse, maybe when your veterinarian is at your place to do vaccinations. Many veterinarians have digital x-ray machines they can take out in the field and you don’t have to bring the horse to the hospital to get good quality films. If there’s confusion regard- ing interpretation of the radiograph, or if the veterinarian doesn’t think it looks quite right, he/she can send it via e-mail to a specialist to look at for another opinion. Today, it’s easy to get some help in figuring it out,” says Grant.
“For a myelogram, a good team (using anesthesia and someone who does radiographs) can do a myelogram in 30 minutes. Like any other technical procedure, myelograms are best done by a team of individuals who have done
it before. There are many equine practices now that can do this. It’s not that hard anymore to get a good diagnosis. Then, you can determine whether it’s a mild, moderate or severe case, and what the horse’s chances are, and you can make a plan accordingly.”
If it’s a horse that only has mild signs, there may be hope with treatment. “Many horses have gone on to race well or go on to grand prix dressage or jumping after surgical treatment,” he says.
Some people wonder if neck conformation might be a predisposing cause, but Grant says the developmental abnormality may affect the way the neck appears. “If you see a long, lean neck, the leanness may be because there is muscle atrophy due to spinal cord compression. A relatively short neck might be the result of an old fracture. So, it’s not like a horse with a short neck or a horse with a really long neck has more problems. They may just look that way because of the problem they have,” he explains.
“There are many horses today that have mild clinical signs, manifested by poor perfor- mance or personality changes such as refusing or shying at jumps because they don’t want to jump anymore. They are probably frustrated because they no longer know exactly where their legs are or where their feet are landing. Their agility is compromised, yet they are still
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equine health