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Horse Owner Information

Have a horse with EPM or has had EPM?  Take advantage of our Client Communication and call us with any questions. To join us in our path to FDA licensing fill out the owner information sheet, look at the study entrance requirements and sign up for our clinical trials.

The first step to returning health to a horse that has been treated multiple times with EPM drugs is to test them. Submit the serum sample to us and we will get your results back to your veterinarian quickly. Equine Consultation Form  If you don't know which tests to select just give us a call at 352-591-3221.  We will consult with you and your veterinarian.

Equine protozoal myeloencephalitis is a rare disease!  What does that mean?  We explain prevalence and incidence for you here.




A horse owner often knows when their horse is under the weather, before the signs of EPM are recognizable.  A paper describing the Early Signs of Equine Protozoal Myeloencephalitis can help you recognize early disease. The paper is based on experimental infections. Click this link to read about our observations.  Ellison 2003Early Signs

Sometimes signs aren't so vague, the horse can be severely wobbly (ataxic) or even so bad, they are unable to get up. And at other times, the horse has been suffering with EPM so long that a dull, distracted demeanor is accepted as "normal".

A therapy plan should include multiple exams, multiple tests, and quick evaluations for a response to treatment.

The antibody found in the horse serum is useful.  How we set up our tests (which protozoan protein, inflammatory markers, markers for autoimmune disease) makes a distinction between tests.

We use surface proteins from the S. neurona organism to test the sample taken from the horse. There are some proteins that are “common” to all coccidia and some that are specific to one of three individual serotypes of S. neurona.  Non-specific tests (IFAT, SAG 2, 4/3) measure the common proteins found on all protozoa. The serotype of S. neurona is determined by detecting antibodies to SAG 1, 5, 6.  The serotype is the level a horse can detect, genetic differences are left to the molecular biologists.

The S. fayeri test measures the amount of anti-toxin found in the serum.  Antitoxin is a reaction to muscle cyst proteins found in S. fayeri infected horses.

Sarcocyst in muscle tissue

A common factor in disease caused by S. neurona and S. fayeri (disease caused by either of these organisms is called sarcocystosis) is inflammation. Inflammation is measured by a serum CRP test.  Horses that respond to anti-protozoal treatment without a reduction in CRP values eventually relapse.


The Cliffs Notes for relapsing EPM are:

1-three conditions are associated with sarcocystosis: S. neurona, S. fayeri toxicosis, and autoimmune polyneuritis;

2-the neurona group describes only 8% of chronic, relapsing/remitting disease;

3-autoimmune polyneuritis, horses with antibodies against myelin covering of nerves, is seen in 43% of relapsing horses;

4-S. fayeri anti-toxin is detected in 49% of horses with chronic neuromuscular disease;

5-the three conditions require different treatment.

A plan is needed to keep these horses healthy and the most crucial aspect of disease management is using your veterinarian to help with the management of the signs using the most up to date treatment protocols.  Testing the serum for CRP levels can let the veterinarian know if the inflammation is controlled.

If you have questions and are a HORSE OWNER and need more information about the appropriate study please use this link: Help   If you would like to update us on the horse after treatment please use this link: Horse update

Please complete this survey designed to obtain treatment effectiveness for Protazil treatment for EPM.  Click here: Protazil Survey