Encephalitozoon cuniculi infections in dogs: a case series.

Encephalitozoon (E.) cuniculi has been occasionally identified as a cause of neurological or renal disease in dogs, but cases are not well documented in the United States. The medical records from a state veterinary diagnostic laboratory for 19 cases of fatal encephalitozoonosis in puppies were reviewed. Clinical histories included depression, inappetence, and progressive neurological signs of short duration. Histopathological evaluation showed brain and renal lesions typical of encephalitis and nephritis, respectively. Molecular analyses of parasites from 13 cases confirmed the identity of the organisms as E. cuniculi strain III. This parasite may be an underdiagnosed cause of fatal canine neurological or renal disease.