1Zoo Atlanta, Atlanta, GA, USA; 2Infectious Diseases Laboratory, Zoo and Exotics Pathology Services, Department of Small Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
An adult male beaded lizard (Heloderma horridum exasperatum) was examined because of anorexia and lethargy of 1-week duration. Diagnostic testing included a physical examination, complete blood count, plasma biochemistry panel, whole body radiographs, and coelomic ultrasonography. A large palpable mass in the mid-coelom was confirmed by radiographs, and a smaller mass in the right lung was identified. Blood values were within reference ranges. The sonogram revealed a homogeneous mass with soft tissue echogenicity. Cytologic results from an ultrasound-guided fine needle aspirate were suggestive of a melanoma.
An exploratory coeliotomy was performed. The lizard was induced with propofol (PropoFlo, Abbott Laboratories, North Chicago, IL, USA; 5 mg/kg IV), an endotracheal tube was placed, and anesthesia was maintained with isoflurane (Isothesia, Abbott Laboratories, North Chicago, IL, USA; 2–3%). Artificial ventilation was provided at a rate of 2–3 breaths per minute. The large mass (10×5 cm diameter) originated in the right lung, with extensive adhesions to the right liver lobe. The smaller mass (2×3 cm diameter) was contained within the right lung. A right pulmonectomy and partial hepatectomy were performed to excise the tumors. Anesthetic recovery was uneventful. The lizard was prescribed butorphanol (Torbugesic, Fort Dodge Animal Health, Fort Dodge, IA, USA; 0.5 mg/kg IM SID for 7 days) and ceftazidime (Fortaz, Glaxo SmithKline, Research Triangle Park, NC, USA; 20 mg/kg IM every 72 h for five treatments).
Histopathologic evaluation of the mass confirmed the diagnosis of melanoma, and there was no evidence of neoplastic cells at the hepatectomy margin.