I have spent the last seven months treating my horse for EPM. We should be done with treatment in two days. Anna looks really good now but I have a strong urge to knock on wood as I type that because relapse is always a possibility.
I would like to share with you what I have learned through this process because, chances are, more than a few of you will have to deal with EPM at some point. Maybe my experience can be of some benefit to you and your horse.
I would like to divide this up into several parts. The first would be “diagnosis”, the second “treatment”, the third “food for thought” and the fourth “resources”.
Part 1: Diagnosis
In mid March of 1999, Anna and I completed our first one day 50 mile ride at the Florida Endurance Classic. We went slow but I was so pleased that she came through with one B and the rest A’s. I was thrilled as this was a big step for my mare and I. The vets were excellent and since there was an FEI part to the ride, no doubt very qualified.
After a week or so of time off, it was back to work. Anna wasn’t quite right. Soon she was intermittently traveling crooked, with her hind end traveling several inches off to the left of her front end. After checking to see if the heart rate monitor was bothering her, then checking for saddle problems, I called my vet, Dr. Suzan Oakley. She came out the first part of April and made the diagnosis of EPM. The diagnosis was made due to muscle atrophy in the right shoulder and mild atrophy over the gluteals. Anna had proprioceptive deficits in all four legs (moderate delay in the front, extended delay in the hind). Tail pull was weak and she had a distressed facial expression. Should be noted that I rode her hard for 45 minutes (turns on the haunches, forehand, tight circles, backing etc) before I could get her to travel crooked prior to the vet’s arrival.
My vet started Anna on pyrimethamine/sulfadiazine 30 ml a day. She also gave her the rabies shot she was due which may or may not have been such a great idea at that point, but more on that later.
A month later she showed mild improvement to my vet. But to me, she was worse as it took no effort at all to get her to travel crooked. Although I believed my vet’s diagnosis because she is a skilled diagnostician and I had a gut feeling she was right, I decided at this point to get a second opinion.
My neighbor’s horse had just been diagnosed with EPM also so we took them both up to the University of Florida vet school. Dr. Maureen Long, a neurologist, saw Anna. She did a spinal tap on her, x-rayed her neck and did a neurological exam. The results were that Anna has some arthritis in her neck which may or may not be effecting her (although I bet that’s why she couldn’t do dressage)plus she had mild weakness in the RF,LH and RH and mild proprioceptive deficits. The spinal came back as a strong positive for EPM. Dr.Long recommended continuing the treatment my vet started. As a side note, Dr. Bryant who vets alot of rides checked on my mare several times while we were at UF and I really appreciated that courtesy. Although both vets felt they had enough to go on to diagnosis EPM, there is no definitive way to prove a horse has it. Some horses with positive spinal taps show no symptoms at all. No one really even knows what causes EPM. Recent controlled studies at UF failed to induce EPM in healthy horses.
My next post will cover a comparison of tx options (including cost), supplements, rehab and other tx considerations.