Oral tumors represent the fourth most common malignancy in dogs and cats. Neoplasms of the oral cavity include both odontogenic and nonodontogenic tumor types. Laryngeal and oropharyngeal tumors are often classified under head and neck cancer by some clinicians and are not discussed in this chapter. The current review discusses the biologic behavior, clinical presentations, and therapeutics of the most common oral malignancies in dogs and cats. A variety of histologic types of oral tumors has been described in the literature1-4.