Successful radiation treatment of undertail fibrosarcoma in a Major Mitchell's cockatoo (Lophochroa leadbeateri).

Abstract

CASE DESCRIPTION: A male Major Mitchell's cockatoo (Lophochroa leadbeateri) of unknown age presented with an ulcerated mass on the ventral tail caudodorsal to the cloaca. CLINICAL FINDINGS: An impression smear of the mass showed spindle cell atypia. Multiple biopsies were submitted for histopathology with inconclusive results. A CT scan revealed a soft tissue mass causing compression of the cloacal lumen. The patient underwent surgical debulking, and a core of the mass was submitted again for histopathology, which reported it as fibrosarcoma. TREATMENT AND OUTCOME: Under repeated general isoflurane gas anesthesia, the patient received a course of definitive radiation therapy totaling 60 Gy and divided in 3 Gy X 20 fractions. By treatment completion, the lesion had decreased in size with necrotic debris on the surface. Surrounding tissues appeared healthy and no adverse effects were observed. As of 1.5 years post-treatment, the mass appears completely healed with no signs of reoccurrence. CLINICAL RELEVANCE: This case suggests that radiation therapy with this protocol could be an effective treatment option for fibrosarcoma in avian species.