Most horses average 90 to 120 days on the medication. Stopping treatment too early, giving only part of the dose, or not dosing daily can lead to resistance to the medication, contributing to relapses and horses that never fully recover. Eight to nine thousand units of vitamin E daily may also be helpful in reducing inflammation. Both pyrimethamine and folic acid are absorbed better when given either one hour before or two hours after feeding hay. Scientists are exploring the safety and efficacy of other drugs in the treatment of EPM, including tetracycline and doxycycline, and diclazuril and toltrazuril.
None are without complications.
Similarly, companies looking into producing a vaccine against the disease are discovering limitations there as well. Advise owners to prevent exposure to the disease in the first place by keeping birds and opossums out of feed and off the premises. Recommend regular vaccinations and dewormings to help decrease stressors that can weaken a horse's immune system. Finally, convince owners to contact their veterinarian at the first sign of neurological disease, so that diagnosis and treatment can be initiated before permanent damage to the central nervous system occurs.