The autonomic nervous system can be affected as part of a more diffuse peripheral nerve disease such as inflammatory polyneuropathy or diabetes, or as a primary disease, such as dysautonomia. Dysautonomia is being diagnosed with increasing frequency in dogs and other species in the Midwest. Affected animals present with absence of parasympathetic and autonomic ganglia and brainstem nuclei degenerate with minimal inflammation. The cause is unknown and treatment symptomatic.