EQUINE PROTOZOAL MYELOENCEPHALITIS


EPM Rehabilitation Summary

There are no published clinical studies, or protocols to follow when rehabilitating the EPM horse. It’s going to take creativity, patience, and intuition on the part of the owner or trainer. Each individual horse will follow a different timetable, and have a different outcome. Making sure that the horse is ready to move forward is imperative, so go through this checklist:

  • The horse has finished the recommended treatment protocol.
  • During turnout the horse shows improving movements and gaits
  • The owner has diligently tried to determine the extent of deficits
  • The owner has conferred with their veterinarian
  • Diet and stress factors have been reviewed to improve immunity
  • The horse has been ground worked and is ready for more
  • The owner is not rushing to fulfill their own schedule

Photograh by Anne Louise MacDonald ©
   © Anne Louise MacDonald  In the shade
One of the most important items from this list is gaining accurate knowledge of the horse’s physical deficits. Use the Tellington TTeam as a Compliment in the Rehabilitation of Horses with Neurological Deficits book to help uncover deficits and begin the recovery process.

If the horse shows many uncoordinated movements, trips often, or has other deficits that make him unsafe to ride, continue to ground work the horse, adding new tasks only when they are ready for it. Consistently asking the horse for more than what it can physically deliver can create stress and promote a relapse. Rehabilitating the EPM horse is a long term process. While the horse may learn to compensate for the loss of feeling in a few weeks, allow at least one year for the damaged nerves to regenerate.

When the horse is unable or unwilling to perform a movement or desired behavior, the owner must consider three reasons why the horse is not performing at pre-EPM levels. First, that the horse has been out of work for months, and is not accustomed to requests by the owner. Second, that the horse has physical deficits in weak muscles, or limited muscle control. Third, that lesions in the brain have caused mental behavior changes.

Defining the Performance Problem

Chances are good that your recovering EPM horse is not going to perform to the standards he held before EPM. Figuring out why he can’t perform is important to helping him recover. For each problem or deficit, think through the possible causes below to find a solution.

Have a second person video the training. Review of the video will help the trainer to see how all parts of the horse are responding to a request, and will show balance problems from a different vantage point. Videos taken at specific intervals can become an informative diary of progress.

Training Tune-Up

If the horse has been out of training for months, he is going to be rusty and perhaps slow to respond to requests by the owner. Fortunately, this is the easiest of the issues to fix. Through slow ground work exercises, ask the horse to respond to your commands. Start with the commands that he performs well, and slowly build the list of moves you request. Use the same patience that you had in training him originally. Frustration and anger will not help the horse.

Pull out the dusty videos or CD’s from your favorite trainer, and spend some time perfecting your approach and timing. Consistent work over a few weeks should show improvement in the horse’s response, if it is training related. The recovering EPM’r will not physically improve in a consistent manor, so be flexible enough to end the training early if the horse tires.

Physical Deficits from EPM

Both weak muscles from time-off and lack of neurological control of muscles form the majority of problems for the recovering EPM horse. The horse can learn to compensate for the lack of feeling, or may eventually generate new nerve pathways, when dealing with deficits in movement. The issues of weakness and control are connected. Giving the horse more turnout time will allow more gentle exercise, more firing of the muscle synapses, and better mental health.

Consider that the horse may have deficits in areas of the body, or layers of muscle that are not visible. The connecting muscles from the neck, chest and vertebrae are important to functions of gait and transition. Atrophied muscles don’t just cause weakness; they can cause stress in other parts of the body as the horse tries to compensate by using different muscles.

Mental Changes from EPM

Autopsies of EPM positive horses show that lesions sometimes form in the brain. Anecdotal stories of subtle changes in personality come from owners and trainers. This aspect of EPM is hard to define, and harder to diagnose. EPM lesions in the brain can affect any body system controlled by the brain, and therefore many mental and physical health issues.

Typical EPM Rehabilitation Issues

Round Pen and Lounge Line

The most commonly reported symptom of EPM is asymmetrical ataxia (uncoordinated) movement of the rear legs. Toe dragging and missteps on sloped ground are two examples of this. This physical deficit makes it hard for the horse to turn tight circles. Work the horse by hand walking uphill to build strength in the hind end.

If the horse has improved in coordination, and can turn without problems, the lunge line or round pen can be utilized for short periods. Watch carefully for tiring, stumbling, or other signals indicating you should stop. If the horse cannot be worked safely in both directions, revert to hand walking.

Changes in Eyesight

Deficits in the eyesight may be caused by lesions in the optic nerve or brain, making them hard to diagnose with a standard eye exam. Episodes of spooking, especially outside of the horse’s normal work area, may indicate problems with eyesight. Long term observations of the horse may be more diagnostic than an eye exam.

Resistance to the bit

If the horse had deficits to the jaw, lips, tongue, or cheeks, his reaction to his usual bit may change. He may not be able to feel it, or it may cause unaccustomed pain. Have an equine dentist perform an exam before making changes to the bit.

Shoeing

EPM horses with limited sensation in one or more legs may have toe dragging, stand with a leg cocked at an angle, or have changes to their gaits. Have the farrier check for unusual wear patterns. Whether the horse is shod or barefoot, make sure the farrier knows of any physical deficits.

Many EPM horses can’t stand for long periods with a hoof lifted. A few are unstable months after treatment. Try placing the horse next to a solid wall to trim or shoe. This may help limit swaying. The horse may become defensive of legs he can’t feel, and kick, pull away, or jump to regain balance.

Locking Stifles

This problem has been reported in some EPM horses. It is not known if the ‘locking’ comes from weakness due to time off, lack of feeling in the muscle, or possibly related mineral deficiencies. Some veterinarians recommend strengthening the stifles by backing the horse. Start with a few steps at a time, working on level ground. Build up to backing many steps, several times per day, and some steps backing uphill.

Downward Transitions

Sometimes the first symptom of EPM is trouble in downward transitions. If the horse can’t feel its rear feet, and the rider is using the bit to ask for a downward transition, the horse can become unbalanced. The horse may have problems compensating for requests to slow down, until he has full feeling of all four feet.

This is one area where the skill of the rider comes into play. The rider’s body position, balance, use of hands, and focus are needed to help the horse. Using a pre-signal such as breathing or an auditory cue will help the horse to know that a request is coming. Consider learning the Centered Riding techniques to help your horse while ground working and under saddle.
 

 January 2012