Unusual presentation of canine Mycobacterium avium infection.

This short communication describes the clinical and morphological findings, diagnosis and treatment of a case of Mycobacterium avium infection in a golden retriever that presented with a progressive nasal swelling and lymphadenopathy. Although well documented in cats, where cutaneous lesions are frequently recognised, canine M avium infection is less commonly reported, and cutaneous lesions are rare. To the authors' knowledge this is the first documented case of canine M avium infection that presented with a cutaneous lesion but no systemic clinical signs. It occurred in a dog with no previously reported breed predisposition and highlights that in cases of cutaneous histiocytic infiltrate in dogs mycobacterial infection should remain a differential diagnosis, even in the absence of suggestive organisms on histopathological examination.