By Rebecca Sims
Equine Protozoal Myeloencephalitis, or, as it is more commonly referred to, EPM. We have all heard of this terrible disease and what it can do to our beloved horses. In December 2019, my horse was severely affected by this disease and it almost cost him his entire career.
It was March of 2019, I was a working student in Wellington for the season, and before the season was almost over I purchased the now 11-year-old Rheinlander gelding, Robes Bieber. When I first acquired Bieber, he had just started schooling some Prix St. Georges (PSG) movements. He had some tempi changes and a very basic knowledge of pirouettes. He was previously an eventing horse, having won the 5-year-old Eventing Championships in Belgium, but then the previous owners switched him over to dressage. That year, we competed at Fourth Level, Developing PSG, and eventually made his debut at Prix St Georges. We qualified for Great American/USDF Regional Championships at Fourth Level and PSG, where we went on to receive Wild Card scores to qualify for the US Dressage Finals presented by Adequan®, in Lexington. In November we made the trek to Finals and in the Fourth Level AA Championship class we finished third, and in the PSG AA Championship we were just barely out of the ribbons.
After Finals, and Bieber was settled back home and had gotten some time off, I decided to just put him on the lunge line. We were lunging in a dry grass field and all of a sudden, while he was going around calmly on the lunge, he tripped and fell completely to the ground. He immediately popped back up and continued trotting on, completely sound, like nothing had happened. The next day I got on him to ride and something was not quite right. His hind end just felt off, but he still looked sound. I figured it was maybe due to some soreness after his crash on the lunge, so I wasn’t too concerned yet. However, after another ride or two, he wasn’t getting any better, so we took him to the vet to see if he could find anything wrong. After explaining what had happened while lunging him and a physical examination, my vet determined he had probably just severely pulled a muscle during his fall and to give him 3-4 weeks off.
It is now January of 2020 and we are back in Wellington for the season. I had Bieber and my Brentina Cup horse, Ultimo, with me for the three months I was there. The first few weeks I was there I lightly started Bieber back again under saddle. I was being extremely cautious and only rode him about 20 minutes, doing super light work, but he never began to feel better. One day, in late January, I took a lesson on Bieber to see what my trainer thought. I had only been riding for a few minutes when she told me to get off immediately. She said something was not right and to call the vet out immediately.
After the vet in Florida came out to look at Bieber, we determined he was suffering from EPM. It was a difficult diagnosis to come across because of several factors. The first was because, prior to his fall on the lunge, Bieber never demonstrated any neurological symptoms. Ultimo, my other horse I had with me, had been treated for cases of EPM twice while I had owned him, but both times he had EPM we noticed the symptoms immediately and put him on treatment so he never had any severe complications with it. Bieber, on the other hand, never presented any signs I recognized. Secondly, there is no tried and true method for testing EPM that has 100% accuracy, unless the horse has died and a vet performs a necropsy. Even a positive blood test just means the horse is positive for exposure to the protozoa but may not have any symptoms of the disease. Unfortunately for us, back in Alabama where I was living at the time, EPM is so prevalent that almost 100% of the horses would have a positive EPM blood test.
When the vet diagnosed Bieber with EPM, we immediately started him on a treatment of Decoquinate, Levamisole, and then Gabapentin to help relieve the nerve pain. The vet told me to not ride him again until I got the all clear from him or my vet back home, but I was allowed to lunge him to try and keep his fitness up. With this treatment, Bieber’s ataxia did not seem to greatly improve, but nothing was getting worse either.
What is EPM
“Equine protozoal myeloencephalitis is caused by infection of the central nervous system with the protozoan parasites Sarcocystis neurona and, less commonly, Neospora hughesi. It is often a progressively debilitating disease and can affect any part of the nervous system, from the front of the cerebrum to the end of the spinal cord.
Equine protozoal myeloencephalitis is considered the most prevalent cause of neurologic disease of horses in the Americas.”
“Clinical signs due to S. neurona infection are dependent on the area of the central nervous system that contains the parasite and the type of damage caused. The onset of the disease may be slow or sudden. Spinal cord involvement can manifest in gait abnormalities, incoordination, ataxia (inability to control voluntary muscle movement), spasticity in all four limbs, and muscle atrophy, whereas brainstem involvement may manifest in lethargy, behavioral changes, and cranial nerve paralysis (facial nerve paralysis, tongue paralysis, difficulty swallowing). Signs may not be the same on both sides of the horse (asymmetrical). Some horses may stand with their feet splayed or lean against walls or other supports. In some cases, the clinical signs stabilize and then relapse days to weeks later. Factors that influence the progression to severe neurologic disease are not well understood.
Cases of EPM due to N. hughesi can have a wide range of clinical signs, including hind limb ataxia and hind limb weakness that progress to more generalized weakness and recumbency. Clinicians at UC Davis have mainly noticed gait abnormalities and ataxia, and that cases diagnosed with EPM due to neosporosis often have concurrent diseases (metabolic conditions, bacterial or viral infections).”
-Taken from UC Davis https://ceh.vetmed.ucdavis.edu/health-topics/equine-protozoal-myeloencephalitis-epm
March of 2020
Due to the rise of the Coronavirus, I decided it was best to leave Florida early and get the horses back safely, since I was not sure if all the closures across the country would have any effect on travel. Once back home, we took Bieber to my vet in Birmingham and decided to switch the medication he was on. We switched him to a treatment of Protazil and, after the switch, we started seeing better results.
About two months after starting treatment with Protazil®, Bieber’s strength and coordination had greatly improved and we were given the green light to begin riding again!
Rehab with Equiband pad
The Rehab Process
Bieber’s EPM case was so severe that he lost a great deal of strength and muscle mass, so rehabbing him was a very difficult and time-consuming process. The protozoa also affects their coordination, so it seems as though they are not aware of where their legs are, and this was probably the most challenging obstacle Bieber had to overcome, and he struggles with it even now.
For the first month we only walked, trotted, and cantered for approximately fifteen to twenty minutes daily. Any lateral movements were extremely difficult for him, due to the loss of his coordination, so I rode most of those at the walk. One key tool that I used in this rehab process, which was highly recommended to me and I truly believe is one of the main reasons Bieber progressed, is the Equiband saddle pad. Besides helping to build his strength back, the band around his haunches seemed to help him be more aware of where his back legs were. The first time I rode him in this saddle pad I couldn’t ride him for more than ten minutes because it was so exhausting to him. However, after just a few short weeks, he made huge strides in rebuilding his strength and was almost starting to trot and canter normally again.
Laura Graves clinic Nov 2020. Photo by Meg McGuire Photography
Winter of 2021
In January of 2021, Bieber and I returned to Wellington for the season. I had high hopes for the three months we were there. It was my goal to get him back in the show ring. However, after the first month of being back in training, my trainer and I decided he just wasn’t quite strong enough and it wouldn’t be fair to him to put him in the show ring before he was ready. He was still struggling with his flying changes and his trot was still uneven. We realized we were pushing him just a bit too much and needed to tone down our exercises so that his muscle strength could catch up. He was putting in his best effort to recover, but I had to remind myself to be patient with him in his rehabilitation process.
It was June of 2021 and Bieber had made huge improvements since our time in Wellington, and I decided he was ready to show again. I took him back out at Prix St Georges and he got two great scores, in the mid-60s. It had been his first show back since November 2019, and I couldn’t have been more thrilled with the results, given everything he had gone through. A few months later, we went to his second show back and made his debut at Intermediate 1, where we earned qualifying scores for the Great American/USDF Regional Championships. In October, we went to the Great American/USDF Region 2 Championships, where he took reserve champion in the PSG Open division and won the Intermediate 1 Open division championship class. I could not believe it! He was barely able to make a flying change in March and here he was, only seven months later, winning at Regionals and qualifying for the US Dressage Finals in Kentucky.
The road to getting Bieber back to being sound and healthy was long and took a great deal of patience from both of us. I had to listen to him so carefully and try my best not to overwork him. He has an incredible work ethic and attitude. He never protests or shows any signs that he is tired or hurting, and he tries his heart out every single day, always wanting to please and do his best. That first year, after his diagnosis, we were not sure if he would ever actually make a full recovery. His symptoms were so severe, but every week after I began riding him again, I could notice just the tiniest amounts of improvement, so that gave me the confidence to keep going and not give up on him. Bieber is now schooling all of the Grand Prix movements, and it is my goal for 2023 to be able to take him into the show ring at that level. He has embraced every challenge head on, so I am confident that we will be able to go out and successfully compete at this level.
I contribute Bieber’s comeback from the EPM not only to my trainer and the vets who helped me diagnose and provide him with proper treatment, but also to his amazing character and work ethic. Without all of those things I do not think that he would have recovered. Battling EPM is not easy. It requires a great deal of patience on everyone’s part. You need to really listen to your horse so that you do not push them beyond what they are capable of at that moment. It can be a difficult journey, but thankfully today we have excellent treatments for this horrible disease, so hopefully no one has to go down this same road.