Squamous cell carcinoma of the skin and digits presents in two distinct forms with different causes and behaviours. The cutaneous (skin) form is typically caused by chronic ultraviolet radiation damage and develops on the thinly haired, lightly pigmented ventral abdomen — similar to sun-induced skin cancer in humans. The digital (toe) form, called subungual SCC, develops beneath the nail bed and is the most common tumour of the digit in dogs. Intriguingly, the digital form disproportionately affects dark-coated large breeds such as Labrador Retrievers and Standard Schnauzers, suggesting a genetic rather than environmental cause. Digital SCC typically presents as swelling of a toe, often with loss of the nail, and can mimic a simple nail bed infection. Both forms generally carry a reasonable prognosis with appropriate surgical treatment, though dogs with multiple digits affected simultaneously have a more guarded outlook.