Nonsuppurative Meningoencephalomyelitis of Unknown Etiology in Mink

A central nervous system disease of mink occurred in three unrelated fur farms in Oregon in September, 1981. Only kits four to five months old were affected. Clinical signs consisted of posterior ataxia progressing to complete posterior paralysis with loss of motor control and sensation. Complete or partial recovery occurred in approximately 1.5 months in most mink. Microscopic lesions consisted of severe nonsuppurative meningoencephalitis and meningomyelitis with vacuolation of the white matter of the brain and spinal cord. Canine distemper virus infection and other recognized causes were ruled out on the basis of clinical signs, history, lesions, or laboratory findings. Experimental inoculations of mink with brain and spinal cord specimens from affected mink failed to reproduce the disease.