Feline oral squamous cell carcinoma (FOSCC) is the most common oral neoplasia in cats. This malignant tumor is locally invasive, has a high mortality rate, and its etiology is not yet known. In humans, head and neck squamous cell carcinoma is associated with tobacco smoke, alcohol consumption, and human papillomavirus infection. 

Herein, a critical review about the potential etiologic factors of FOSCC was performed, considering publications between 2000 and 2022, aiming to synthesize all available scientific evidence regarding this issue. Recommendations of the PRISMA statement and the Cochrane Collaboration were followed, and the PubMed database searched by using the MeSH terms MeSH terms "oral", "mouth", "lingual", "labial", "gingiva", "carcinoma", "squamous", and "feline". The selection process for eligible studies was based on specific inclusion and exclusion criteria and the quality of the studies assessed.