Uropygial Gland Keratoacanthoma in a Saker Falcon () Associated With Herpesvirus Infection: Clinical and Pathological Findings.

Abstract

A 24-year-old female saker falcon () was presented for a hyperkeratotic lesion associated with the uropygial gland. Owing to perceived anesthetic risks, a conservative medical approach was initially chosen over surgical excision. The treatment involved local debridement and supportive care, which provided temporary improvement. However, the lesion recurred multiple times, leading to the decision to perform complete surgical excision of the uropygial gland. The falcon underwent cardiopulmonary arrest during the procedure and was unresponsive to resuscitation. Histological analysis identified a compact cystic mass characterized by atypical proliferation of the keratin and squamous cell layers, consistent with an infiltrating keratoacanthoma of the uropygial gland. Additional findings included necrotizing hepatitis, focal splenic necrotic lesions and white pulp depletion, pyogranulomatous nephritis, pulmonary edema, and infiltrative chronic-active enteritis. Amphophilic intranuclear inclusion bodies were observed in the basal layer of the uropygial mass and in hepatocytes. Immunohistochemistry confirmed the presence of avian alpha-herpesvirus antigen in liver, kidney, and uropygial gland. To the authors' knowledge, this is the first documented case of uropygial keratoacanthoma in a bird of prey.