Polyarteritis nodosa and rheumatic heart disease in a dog.

A 12-year-old spayed Corgi-type dog developed an acute febrile illness about 2 weeks after excision of a subcutaneous arteriovenous fistula. The dog was moribund after 1 week of illness and was euthanatized. Necropsy disclosed uncommon lesions comparable to those of polyarteritis nodosa and rheumatic heart disease of human beings. The pathogenesis of the arterial and cardiac lesions was not established, but was consistent with that of an immune-mediated mechanism.