Equine protozoal myeloencephalitis is a neurological disease in horses caused by Sarcocystis neurona and Neospora hughesi causing progressive neurological deterioration and significant welfare impact.
EPM causes progressive neurological deterioration including ataxia, weakness, and muscle wasting that profoundly affects a horse's ability to move, balance, and function. Severely affected horses risk falling and causing injury to themselves and handlers. The distress of losing neurological function and the limitations imposed on movement and normal behavior represent significant welfare concerns. Treatment decisions involve careful welfare assessment weighing potential for improvement against the burden of ongoing neurological disease. Euthanasia may be the most humane option for horses with severe irreversible neurological deficits.