Cures for EPM in Horses

EPM--Equine Protozoal Myeloencephalitis--is a degenerative disease of the central nervous system triggered by protozoal parasites. These protozoa cause incoordination, muscle atrophy and loss of balance in infected horses. While the disease is debilitating, it is not painful to the horse; neither is it contagious between horses. While most horses will probably be exposed to the protozoa believed to be carried in the feces of opossums, only a small number will actually come down with the disease. Although there is no definite cure for the disease, two treatments have shown good results.

  1. Current Treatment for EPM

    • According to the University of California at Davis website, the only currently approved veterinary treatment for EPM is the anti-protozoal drug Marquis by Bayer. Treatment consists of one oral dose per day and usually takes one to two months to kill the protozoa. While no treatment for EPM is totally effective, the success rate for this drug is approximately 70 percent.

    An Early Treatment

    • A combination of Sulfadiazine - Trimethoprim - Pyrimethamine was one of the earliest treatments for EPM and is still in use today. While this drug combination does not actually kill the protozoa, it limits their ability to use folic acid and thus reproduce. This treatment usually takes three to seven months before the protozoa are destroyed. During this time the infected horse is at risk for anemia due to limited folic acid.

    Prevention

    • Researchers are still looking for a cure for EPM.

      Researchers are still looking for ways to halt this disease; as of 2010 their focus is to stop the protozoa before they can enter the central nervous system. In 2000 an EPM vaccine was conditionally approved and is now being used under field conditions. In the meantime, the Bayer Equine Connection recommends owners take preventative steps to avoid exposure to the disease. These steps include keeping feed rooms and containers closed, using feeders difficult for wild animals to access, and cleaning up dropped feed immediately to keep birds and scavengers away. The website also recommends feeding heat-treated cereal grains or extruded feeds as the process used to produce these seems to kill the protozoal spores.