Equine protozoal myeloencephalitis or EPM in horses is a neurological disease that is caused by a small parasite. The parasite is carried by opossums. Equine are exposed to the disease if they eat feed or drink water which has been contaminated by feces from opossums.

The disease symptoms vary greatly. These depend on the part of the nervous system which has been attacked. The protozoa could cause the equine to be left with lesions on the spinal cord and the brain stem. This disease is most prevalent during the summer and the fall months, with the fall being the time it is found most. The symptoms are quite slow in developing and could be present many days after infection has occurred.

It is not easy to make a diagnosis of EPM in horses as there are several neurological diseases with similar symptoms. The symptoms are not the same for each horse. The horse may suffer from weakness and muscle atrophy. It may also experience difficulty when it tries to swallow. The equine may suffer from pain in its back, weakness and a distinct lack in co-ordination.

If the equine has a mild form of the disease, it may suffer from slight lameness and mild stumbling. If this is not treated in time, the horse will eventually be unable to stand up or swallow. In severe cases such as these, the horse is at risk of death. The equine may indicate drooping eyelids and a tilted head. The disease can affect horses of any sex, breed or age. The risk is much higher in younger horses and those that are frequently transported.

Prevention of the disease is possible in stables that do not attract opossums as they are the carriers of the disease-causing organism. Opossums are not selective about their eating fancy. They eat virtually anything, including dead animals, horse feed, dog and cat food.

To prevent these animals from invading your property, you should make sure that all food stores are secured. If there are dead animal carcasses on your property, you should make sure that these are buried as soon after death as possible. Food that has been spilled should be cleaned up immediately. If your property is at risk of opossums and you suspect that they are around, you should attempt to trap them in a humane way and remove them accordingly. You can choose to fence your property with specially designed fencing to keep opossums out. This is a good option if they have become a nuisance to your other animals.

This is a dangerous disease and horses that show signs of it should be examined by a veterinary specialist as soon as possible. A quick diagnosis and proper veterinary care will allow the horse to recover from the disease. The infection may leave the animal with permanent damage. The vet will normally examine the movement and gait of the equine. It is vital that spinal fluid and blood tests are undertaken to rule out diseases such as viral encephalitis and West Nile virus.

Different types of drugs will be used during treatment for EPM in horses. This will include anti-microbial, anti-protozoal and anti-inflammatory drugs. The treatment process for the disease is a lengthy and fairly expensive one. Unfortunately, the available treatment options are not always a success.