Epidemiologic analysis of oral and pharyngeal cancer in dogs, cats, horses, and cattle.

Four hundred sixty-nine oral-pharyngeal malignancies diagnosed in dogs, cats, horses, and cattle and submitted to the Viterinary Medical Data Program between March 1, 1964, and Dec 31, 1974, were analyzed. Of these cases, 84% were in dogs. The most frequent oral-pharyngeal cancer in dogs was melanoma; in cats and horses, it was squamous cell carcinoma. In dogs, the risk of developing melanoma increased more with age than did the risk of developing squamous cell carcinoma and fibrosarcoma. Male dogs had significantly greater risk of developing fibrosarcomas and melanomas than did female dogs. The German Shorthaired Pointer, Weimaraner, Golden Retriever, Boxer, and Cocker Spaniel breeds had significantly higher risk and Dachshunds and Beagles had significantly lower risk, as compared with all breeds combined. There was no significant difference between observed and expected numbers of tonsillar carcinomas diagnosed at veterinary colleges located in small urban areas (less than 50,000 persons) as compared with large urban populations (greater than 500,000).