Abstract
An eight-year and two-month old castrated dog was presented with pus-like exudate from the left ear. As a large number of bacteria and neutrophils were observed in the smear of the exudate, the dog was diagnosed as having bacterial otitis externa. Though the dog was treated with medication of antibiotics and repeated cleaning of the ear, no improvement was recognized. A nodule, 5 mm in diameter, was observed in the left external auditory canal at eights year and nine months of age and the nodule became as large as the entrance of the ear canal at eight months later, when it was removed surgically using a semiconductor laser unit under inhalation anesthesia. The dog was medicated by an antibiotic and β-glucan formulation after the operation and the symptoms of otitis externa disappeared immediately. The nodule was histopathologically diagnosed as a well-differentiated squamous cell carcinoma associated with hyperplasia of the ceruminous gland. No metastasis and recurrence of the tumor has been observed in the four years and three months since the surgery.
