Pathogenes Inc.

Select the best treatment option for a horse with EPM

 The published data for chemotherapy for S. neurona shows that strains vary in the susceptibility to three drug classes available. The pyrimethamine anti-malarial drug is effective against SnSAG 1 and SnSAG 5 strains. Oroquin-10 is effective against SnSAG 1, SnSAG 5, and SnSAG 6 strains.  The triazines are effective against some SnSAG 1 and SnSAG 5 strains and partially effective against some SnSAG 1 and SnSAG 5 strains.  Increasing the dose of the triazines to 10X increases efficacy but can be toxic.

Prevention of equine coccidiosis at the label dose of the triazines is not effective against SnSAG 1 or SnSAG 5 strains.  Oroquin-10 is effetive against other coccidia in other species at 1/10th the treatment dose.  Studies are underway to determine the mechanism of protection in horses for the prevention of relapse or re-infection.  A top dress medicated supplement for the prevention of coccidiosis in horses is available by prescription at Franck's Pharmacy and may prevent disease or re-infection due to exposure.   

A field trial using Oroquin-10, a 10 day drug treatment for EPM is available.  The non-toxic drug is absorbed quickly and kills intracellular pathogenic protozoa that can evade other treatments that lead to relapse conditions.  Oroquin-10 is non-toxic to animals, and is formulated to stimulate protective immunity during treatment.  

The in vitro efficacy against SAG 1 and SAG 5 phenotypes has been established.  Challenge trials are on going.  The drug is safe in horses at 10X the prescribed dose.  No side effects have been reported. This drug may be an effective therapy against equine babesiosis (equine piroplasmosis) (David Lindsay, 2001). 

To participate in the trial we need horses with a diagnosis of EPM from a veterinarian and evidence of antibodies by ELISA titer >16 or a positive equine piroplasmosis test.  In cases with a grade lV ataxia we would like a purple top tube with the first ELISA test submission.  The attending veterinarian may elect the 10 day treatment protocol consisting of one tube daily.  There are no concomitent feed or drug restrictions.  We prefer no other medications given during treatment but any additonal therapy deemed necessary does not disqualify participation.  At the end of treatment a second antibody titer is evaluated in 4-6 weeks.  A horse is eligible for the trial by submitting a serum sample for ELISA testing or evidence of a positive piroplasmosis test (submit email results to sellison@pathogenes.com and indicating a desire to participate in the trial).There is no charge to participate in the trial.  Testing by Peptide ELISA is $38.00 and trial drugs are purchased through Franck's Pharmacy.  

Successful treatment of EPM begins with an accurate diagnosis.  Treatment of Sarcocystis in the horse is most effective in the early stages of disease.  

    The most effective method of identifying these horses is by a a change in titer and physical/neurological exam by an experienced veterinarian. A specific titer that detects antibodies against Sarcocystis that cause disease (EPM), an antibody profile, is critical to understanding the best treatment options as well as prognosis.  Tests that detect Sarcocystis falcatula or S. neurona strains that do not cause disease will be expensive to the horse owner and delay a correct diagnosis. 

    We identify three strains of S. neurona that have been associated with EPM in the horse using the Peptide ELISA test.  By monitoring the antibody profile the management of EPM becomes less frustrating.

    We can identify the prevalence of disease on a farm or stable.  The prevalence of disease can be used with antibody titers to determine risk and help with the differential diagnosis of EPM.  Call for details.

Treatment of "relapsing" EPM in the horse.

Marquis (click on name to see data displayed in a graph) levels in the serum and CSF from horses given oral paste are shown in the table. 

FIELD DRUG TRIAL for HORSES

OROQUIN-10 IS AVAILABLE TO VETERINARIANS FOR THE 10 DAY TREATMENT OF EQUINE SARCOCYSTOSIS (EPM) IN THE HORSE via OUR CLINICAL TRIAL. 

FDA safety data is available by request. 

What do Phenotype and Drug Class mean when you treat EPM?

Drug therapy and phenotype