Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by protozoal parasites, with significant welfare implications from neurological deficits, treatment requirements, and rehabilitation needs.
EPM welfare management encompasses both the acute welfare emergency of severely affected horses and the rehabilitation welfare of those recovering from neurological damage. Horses with severe ataxia and recumbency face significant suffering and secondary welfare problems — pressure sores, aspiration pneumonia, and psychological distress from inability to move normally. The decision about when neurological damage is severe enough to warrant euthanasia rather than extended treatment and rehabilitation involves careful assessment of recovery potential, welfare during treatment, and quality of life post-recovery. Horses that recover partially but retain significant neurological deficits may require retirement from ridden work — a welfare-positive decision that prioritizes the horse's safety and comfort over continued athletic use.