After a description of the principal tumors encountered in the oral cavity of domestic carnivores, the clinical study presents the three successive facets of the diagnostic process : identification of the tumor, detection of metastases, histologic diagnosis. The indications for surgery and the pre-operative preparation are briefly described. Among the four possible surgical procesures : electrocautery, cryosurgery, hyperthermia and surgical excision it is especially the last method which is explained in detail by specifying the distinctive characteristics of the surgical intervention depending upon the location and the extension of the tumor within the oral cavity.