Complete Ablation of Vertical Auditive Conduct and Ear Pinna in a Dwarf Hamster (Phodopus sungorus) with an Aural Spontaneous Squamous Cell Carcinoma

Abstract

A 1-year-old male dwarf hamster (Phodopus sungorus) with an inflammation of 7 days' duration in the right ear was examined. Abnormalities noted on physical examination were limited to the right ear and an anal mass. The right ear showed swollen skin and a yellowish secretion. The pinna presented scabs and ulcers, probably secondary to the scratching. Cytological examination of the secretion revealed rod-shaped bacteria and neutrophils. The anal mass was a freely movable nodule 1 mm in diameter attached to the anal skin. Initial treatment consisted of antibiotics and antiinflammatory drugs. After an incomplete response to the treatment, surgery was proposed. The surgical procedures consisted of right ear pinna and vertical canal ablation, and excision of the anal mass. The animal recovered uneventfully. All the samples were submitted for histologic examination. The diagnosis was aural squamous cell carcinoma (SCC) and anal papilloma. Although many neoplasias have been described in laboratory rodents, cutaneous SCC is underreported in rodents kept as pets, especially in hamsters. The case here describes an aural SCC that caused a nonresponsive otitis externa in a dwarf hamster. The tumor was successfully removed and the otitis resolved completely. To the authors' knowledge, this is the first report of ear SCC resolved after surgery in a dwarf hamster.

Key words: aural, hamster, rodent, squamous cell carcinoma, surgery