Squamous cell carcinoma (SCC) is a malignant tumor that has been reported in several organs of different dog breeds. An 8-year-old Shih Tzu, an intact male dog, came to an animal clinic in the Thonburi area, Bangkok Province, Thailand, and a mass of 4.5 × 4.5 cm (width × length) by size was found at the submandibular area. Surgical excision to remove the mass and subsequent histological examination identified the mass as SCC. After conducting the surgery and follow-up, the mass was recurrent at the same location after 33 days and a dog died. Therefore, one of the possible reasons for the death of the dog could be SCC metastasis.