Abstract
Clinical features and treatment results of 25 cases of ear canal tumors in dogs and cats, surgically resected in one private hospital between 2001 and 2015, were reviewed. Twenty one cases were small, well defined masses arising from ventral canal (VC, 18 cases) or horizontal canal (HC, 3 cases), and other 4 cases were feline inflammatory polyps. Out of 19 dog cases, 17 were diagnosed histopathologically, in which 12 (71%) were benign, and 5 were cerminous gland adenocarcinoma (CGAC, 3 were non-invasive, 2 were unknown). All dogs received conservative surgery (mainly lateral ear canal resection: LECR), after which no recurrence was observed except for a dog with CAGC at HC (recurred 1.5 months after excisional biopsy following LECR). Two cats with CGAC (non-invasive) located at HC or VC were disease free for 43 months after total ear canal resection or for 35 months after LECR, respectively. Inflammatory polyps in 4 cats did not recur after resection by traction followed by prednisolone administration. These results suggest that benign or non-invasive tumors are predominant in well-defined, ear canal masses in dogs and cats, most of which can be cured by conservative surgery.
