Diagnosis and treatment of truncal cutaneous pythiosis in a dog.

CASE DESCRIPTION

A 4-year-old spayed female Boxer was evaluated for a cutaneous mass located on the dorsum. The mass had been present for 6 weeks and was increasing in size.

CLINICAL FINDINGS

A mass of approximately 10 cm in diameter was detected on the dorsum cranial to the right ilial wing. Histologic examination of a tissue sample from the mass led to the diagnosis of cutaneous pythiosis. Computed tomography of the abdomen and the mass were performed and revealed a contrast-enhancing soft tissue mass of the dorsum and enlarged intra-abdominal lymph nodes.

TREATMENT AND OUTCOME

The dog underwent surgical excision of the cutaneous mass, including 5-cm skin margins and deep margins of 2 fascial planes. The mass was completely excised on the basis of results of histologic examination of surgical margins. The dog received itraconazole and terbinafine by mouth for 3 months following surgery. Recheck examination at 20 months postoperatively showed no signs of recurrence of pythiosis at the surgical site.

CLINICAL RELEVANCE

Aggressive surgical excision in combination with medical treatment resulted in a favorable long-term (> 1 year) outcome in this dog. Thorough workup including diagnostic imaging and lymph node evaluation is recommended. If surgery is to be performed, skin margins of 5 cm and deep margins of 2 fascial planes are recommended.