Equine Myofibrillar Myopathy (MFM) is a condition related to the muscles that, while actively being researched by owners, veterinarians, and professionals, is still relatively mysterious to researchers. At the moment, professionals have observed that the muscle disorder seems to only affect Warmblood and Arabian horses.
While the exact cause is still unknown, it is speculated that Equine Myofibrillar Myopathy is caused by an underlying abnormality in the cytoskeleton. While the thought of managing such a new condition may seem daunting, an informed and dedicated horse owner can choose to follow a certain “management plan” that has proved to be useful for horses affected by this muscle disorder in the past in order to manage the condition in their horse. Continue reading for more information about Equine Myofibrillar Myopathy, as well as the different management options available as more is discovered about this mysterious muscle condition.
What Is Equine Myofibrillar Myopathy?
Equine Myofibrillar Myopathy is still in the process of being investigated and examined by professionals in order to come to a conclusion regarding its causes and proper treatment. Currently, what is known about the condition is that it may be caused by underlying abnormalities in the cytoskeleton. This condition mainly seems to effect Arabian and Warmblood breeds, and in the case of Arabian horses, it causes “tying up”, or muscle pain, being “sour” under saddle, unwillingness to move, and stiffness.
“Tying up”, clinically referred to as exertional rhabdomyolysis, is a common condition associated with Equine Myofibrillar Myopathy. In most cases, it usually causes a general lameness in the hind legs, decrease in energy level, soreness and stiffness, and unwillingness to go forward. Horses with Equine Myofibrillar Myopathy have also been known to sweat profusely. This has been noted to happen during very light workouts, or even during rest, which of course is a major cause for concern.
It has been observed that Warmbloods affected with Equine Myofibrillar Myopathy do not commonly experience tying up like Arabians do, but they do show poor performance under saddle, unwillingness to go forward, and they may show signs of weariness or soreness. Cases of MFM in Warmbloods have also shown unaltered activity in serum CK and AST.
To the individuals and professionals who study the condition, Equine Myofibrillar Myopathy seems to be some form of exercise intolerance. Though the causes and symptoms of MFM have proven to be a bit baffling for horse owners, veterinarians, and scholars alike, there are options to help horse owners safely manage horses affected by the condition in order to prevent the horse from feeling fatigued, sore, or hostile under saddle or during exercise.
Options For Managing Equine Myofibrillar Myopathy
The first step in helping your horse manage the condition is to get a professional diagnosis from your veterinarian. The symptoms that are usually present with Equine Myofibrillar Myopathy are easy to confuse with other conditions, such as saddle sore, inflammation of the vertebrae, and suspensory injuries. Before any steps are taken to find options for treatment, it is extremely important to make sure that you have an official and professional diagnosis to keep your horse safe. Like with any other medical condition, it can be considerably dangerous to administer treatment or any sort of management plan without making sure that the horse is definitely afflicted with the condition you suspect it to be. Always confirm with your veterinarian before administering any treatment to your horse or making any changes to their diet or exercise regimen.
Once it has been officially confirmed by a veterinarian that your horse has developed Equine Myofibrillar Myopathy, there are a few steps you can take to manage the condition. The most important thing to keep in mind is that as this condition is fairly new and very little information is available about the condition, the medical community still lacks the proper knowledge on what the condition is exactly, as well as treatment or possible cures. At the moment, treatment is not an option, but you can help your horse manage MFM.
The first step in the management of Equine Myofibrillar Myopathy is to minimize rest. This may come as a surprise, and most owners would probably want to combat soreness and pain with rest, but regular turnout with companions is recommended and encouraged.
Exercise and workouts can and should be reintroduced, but at a gradual rate. It is recommended to take several weeks working at a brisk walk and trot before even working up to a canter. This is to prevent any over-working of the muscles as they recover.
When it comes to the horse’s diet, it has been observed that diet may not be as important as exercise and activity when it comes to treating MFM, but there are still a few changes that can be made in order to improve the horse’s chances of successfully managing the condition. Horses diagnosed with Equine Myofibrillar Myopathy should receive supplementation for complete proteins, such as whey. They should also receive complementary proteins, such as soy. Supplementations that focus on certain amino acids may be beneficial, as well.
As stated in a 2018 publication by Michigan State University’s Veterinary Medicine program:
“At present we recommend a diet with low to moderate starch and sugar content, fat added if needed for weight and the addition of a whey-based protein supplement to add muscle bulk. We strongly encourage owners to utilize an equine nutritionist to provide a balanced diet.”
If you have received an official diagnosis of Equine Myofibrillar Myopathy for your horse, it is a good idea to start designing a management method as soon as possible to help your horse remain as pain and stress-free as possible.
As the medical community works to uncover the mysteries of Equine Myofibrillar Myopathy, the best that any owner can do is develop a management strategy with their veterinarian that is best suited for their horse, keeping this information in mind.
Every horse is different, and the condition has the potential to affect your horse differently than it may affect another horse.