There are three important points to keep in mind during the treatment phase. First of all, don’t give up. Your horse might look really hopeless at some points during treatment (i.e. unable to keep his balance) or have phases where she looks really good followed by serious backsliding. This can be heartbreaking and frustrating. However, sometimes the horses that look the worst off recover the quickest. And horses like mine, who have milder cases, can take a long time to heal. Nobody knows why this is the case but the key here is persistence. Secondly, be flexible. What works for the horse down the road may not work for yours. This is a highly variable process. Thirdly, be prepared to spend some bucks. I still refuse to total the cost because I really don’t want to know how much I’ve spent. All that said, I’ll move on to the medications.
I am familiar with the traditional medication (pyrimethamine/sulfadiazine) and Baycox (aka Toltrazuril). There is also a new medication called NZT but I am not familiar with it. My vet and the vet at UF recommended the traditional medication so that’s what I used for 6 months. It is an antibiotic that works by boosting the immune system to fight the protozoa (as I understand it). It costs $140 a month, give or take what mark up your vet tags on. In addition, you will add on monthly vet checks with anemia levels drawn. This treatment typically lasts 6-12 months. My horse seemed to get better, slide back, get better, slide back an infuriating amount of times. This can be caused by the die off of protozoa which temporarily worsens symptoms. The medication is a pain to deal with because it has to be given on a relatively empty stomach (2-3 hours after food has been ingested and no food given 1 hour after administered). You have to drench the stuff which most horses think is nasty tasting then not give them any treat afterwards. I’m surprised my horse still likes me after me starting every morning for 7 months coming at her with a syringe of the stuff. By the end of six months on this, Anna was traveling straight about 95% of the time, her placing test on the front feet was normal and she was only slightly delayed on the hind legs (used to take her 4 seconds to figure out her legs were crossed and how to uncross them, at that month it was less than a second-not quite normal but close). I can describe this test if anyone is interested. Her gluteal atrophy was gone, her attitude much improved and her rear end was stronger. She still had mild shoulder atrophy. By the way, the sooner you catch this thing, the better your odds are of healing the atrophy. At six months, I was faced with three to four more months of treatment. However, my neighbor’s horse had steadily declined on the traditional meds and had switched to Baycox. She had dramatic improvement on the Baycox in a very short time. More was known about Baycox at this point so I decided to get the Baycox and combine it with one last month on the traditional meds. My vet, after seeing the results with my neighbor’s horse, was in full support of this.
Baycox is a new drug that has not yet been approved by the FDA but can be special ordered by your vet through Bayer in Canada. The flat cost is $550 for a 28 day treatment including shipping. Your vet can of course mark it up to whatever the market will bear. Pray that your vet has mercy on you. This drug actually goes in and kills the protozoa directly (as I understand it). It usually takes 28 days to treat a horse. There appear to be no side effects with this medicine. It is easy to administer; I just pour it on Anna’s feed or you can drench it. The only problem I have heard is with relapse. This may be connected with insufficient dosing. It says to give 50 ml per day to any horse. I think that may be fine for my Arab but a heavier horse may need a bit more. Anyway, there are alot of unknowns because this is a new treatment. If I had to do it over again, I would start with the Baycox. After three weeks of Baycox, Anna could full out gallop a 15 meter circle around me leaning like a barrel horse. She looked completely normal to the left and only showed some slight weakness to the right in her left hind but this was at a full gallop. Her strength may improve since she’s had 7 months off but even if it doesn’t, her lasting effects at this point appear to be minimal. Her placement test is also normal now and her shoulder atrophy is improved.
No matter which treatment you chose, it is highly recommended to supplement with Vit E. KV Vet supply has a Vit E 8,000 designed to be the right dose for EPM treatment. It costs $70 for a 4lb container. Anywhere from 8,000-10,000 I.U.s is recommended. I used the E 8,000 but also used an E/Se supplement because we are Se deficient in Florida. Be careful not to over do the Se when adding E because the Se can be toxic. I used Lixotonic (like Red Cell) from Anico Vet Supply to keep my horse from getting anemic (she never did) and Fast Track probiotic to protect her stomach. My neighbor used an immune booster from Meadow Sweet Acres Herbs that she liked (didn’t go over well with my horse) and flax seed (which I am going to try). Some people use Equistem or Levimisole but I have no experience with either of those.
According to the UF vets and an article on EPM rehab in The Horse magazine, you should continue to work your horse on a limited basis to prevent further muscle atrophy. No doubt this is good advise for some horses but, if I were to do it again, I would leave my horse alone (with turn out) and let her heal. As it was, I did light riding for a time but I could tell this was not helping matters. When Anna acts tired there is something very wrong so I did not “push her through it” as advised. I tried lunging which didn’t work and stressed her out because she didn’t have good enough balance to do it, poor thing seemed to feel embarrassed. So I tried ground driving which was tiring for me and didn’t seem to help her. Then I tried some TTouch techniques (promise wrap, stretches, varied heights of cavalletti designed to get her to realize where her hind end was), Anna was very patient with all this but I don’t think it had much effect. Any of these ideas may work very well for another horse but Anna got better when I finally quit worrying her and left her alone. Grooming and sweet talk seemed to comfort her though. Some horses get really grumpy and sensitive during treatment so you might even need to minimize grooming.
I kept a journal of how Anna was doing so that I could see any patterns to her recovery. That helped me to remain a bit more objective and not lose hope. I also took pictures of her from the sides and down along the back so that I could compare any changes in atrophy.
Vaccines and Wormers during Treatment
The rabies vaccine and /or starting treatment wiped Anna out for an entire week. Given that the immune system is already stressed, I would avoid all vaccines during treatment. That is my opinion only and I’m not a vet.
As for wormers, Ivermectin and Quest tend to really set horses back that are being treated for EPM. Anna was not herself for three days after using Ivermectin. Panacur did not seem to adversely effect her and has been used with no ill effect on other EPM horses. However, I am now having fecal checks done and, unless I start to see worms, I’m not worming at all. If I do, I will likely use Strongid once a year and Panacur the rest of the time.
In the next section, I will include some thoughts on prevention.