An Epidemiological Study of Equine Protozoal Myeloencephalitis in Texas

Program year: 1996/1997Digitized from print original stored in HDREquine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease in horses caused by the protozoan Sarcocystis neurona. While new discoveries about the life cycle of the organism and its hosts have recently been made, much still remains unanswered about treatment, prognosis, risk factors, and the spread of the disease over time. A case series with long-term follow-up and a case-control study were conducted at Texas A&M University using 82 confirmed EPM cases and five control groups. The case series was used to describe the population of EPM cases at Texas A&M and evaluate response to treatment and prognosis. The case-control study used logistic regression to assess age, breed, sex, and month of admission as risk factors for EPM. In the case series, age was found to have a significant effect on the tine of relapse and chance of survival, but not on the number of relapses. Breed and sex had no effect on the number of relapses or the chance of survival. The case-control study did not find that aqe or sex were risk factors for EPM, however there was a breed predilection in favor of Thoroughbreds. EPM cases were less likely to be admitted in the months of August, October, November, February, and March as compared to January