Cutaneous and mammary tumours of hamsters are extremely common, in particular in Russian hamsters; it is important not to confuse skin tumours with bacterial infections, delaying the diagnosis as well as the appropriate therapy. Skin tumours may occur at any site: head, auditory canal, trunk, abdomen, anus, limbs. The tumours may be benign or malignant; in some cases the origin can be viral (correlation with the hamster papovavirus, HaPV), and they can be multiple.
Internal tumours are difficult to diagnose before they reach a very advanced stage and they are rarely treatable. In contrast, skin and mammary tumours may be surgically excised and, if treated in time, the prognosis is good.
