Red, inflamed gingiva is a common oral exam finding in cats. In the initial stages of periodontal disease, the inflammation is confined to the gingiva and is termed gingivitis and considered reversible. Once the disease progresses to periodontitis, the condition is no longer reversible. It can be challenging for small animal practitioners to differentiate between gingivitis, periodontitis, and stomatitis, especially when it pertains to young cats. Early-onset gingivitis (EOG) and aggressive periodontitis (AP) are recognized clinical entities in young cats. In 2022, a study published in the Journal of Feline Medicine and Surgery found that “moderate-to-severe periodontal disease was radiographically confirmed in 78% (21/27) of cats with moderate-to-severe EOG (early onset gingivitis), compared with the evidence of periodontal disease noted in 30% (8/27) of cases during awake oral examination. Horizontal bone loss, along with missing teeth, were the predominant radiographic features noted in 89% (24/27) of cases. Two cats developed feline chronic gingivostomatitis (FCGS)-like lesions, and seven cats exhibited worsening of aggressive periodontitis (AP).” This is an important finding because it demonstrates that a young cat with “early onset gingivitis” can have radiographically proven periodontitis and may even go on to develop stomatitis. Buccal bone expansion (BBE) refers to bulbous enlargement of the periodontium in domestic cats. Clinically, BBE is characterized by gingiva that appears firm and bulbous on the buccal aspect of affected teeth as well as gingivitis and variable amounts of root exposure and pocket depth. Radiographic findings of BBE include thickened buccal alveolar bone, varying degrees of attachment loss +/- tooth resorption. Often, there is also vertical bone loss. Tooth resorption (TR) is the most common disease affecting the dental hard tissues in domestic cats. It is believed that at least one-third of cats may develop TR during their life, and the risk of developing TR increases with age. The etiology of TR in domestic cats remains unknown. Radiographically, a tooth with type 1 resorption will demonstrate a focal or multifocal radiolucency present in the tooth with otherwise normal radiopacity and normal periodontal ligament space. On a radiograph of a tooth with type 2 resorption: there is narrowing or disappearance of the periodontal ligament space in at least some areas as well as decreased radiopacity of part of the tooth. On a radiograph of a tooth with type 3 resorption, features of both type 1 and type 2 resorptions are present in the same tooth. Oral squamous cell carcinoma (SCC) is a locally aggressive, devastating disease in cats. Occasionally, cats with SCC will present with the clinical finding of a loose tooth or teeth, which may be mistaken for periodontal disease. Significant lysis of bone should prompt the practitioner to search for alternative reasons beyond periodontal disease.