Chronic gingivostomatitis (CGS) refers to a clinical syndrome in which severe, ulcerative, and/or proliferative inflammation is widespread throughout the oral cavity. The term oral mucositis, with a qualifying reference as to location (eg, alveolar, buccal, labial, caudal), has recently been adopted by the American Veterinary Dental College to more specifically describe oropharyngeal inflammation. For example, caudal mucositis refers to mucosal inflammation that involves tissue caudal to the dental arches including the soft palate dorsally, the buccal mucosa laterally, and the palatoglossal folds caudally.1 Caudal mucositis and widespread buccal mucositis are key clinical features of CGS in cats, in that mucosal inflammation extends well beyond the immediate vicinity of the teeth. In contrast, periodontal disease and tooth resorption affect individual teeth, so inflammation associated with those diseases tends to be localized to the alveolar mucosa and occasionally the buccal mucosa. CGS, periodontal disease, and tooth resorption can all be present in a single patient.