Cerebrospinal nematodiasis in prairie dogs from a research facility.

Baylisascaris spp larvae were determined to cause CNS disease in 3 prairie dogs maintained at a research facility. Clinical signs consisted of ataxia, stumbling, and head tilt, which progressed to severe torticollis, paddling in lateral recumbency, and loss of the righting reflex. Gross lesions were not found at necropsy. Microscopically, the cerebellar white matter and medulla oblongata were most severely affected and had numerous sections of large ascarid larvae. Our findings indicated that natural infections of Baylisacaris spp larvae can cause CNS disease in prairie dogs. Also, Baylisascaris spp larval infection should be considered in differential diagnoses of CNS disease in prairie dogs.