A histiocytoma, also known as canine cutaneous histiocytoma, is a benign skin tumor comprised of histiocytes. A histiocyte is a cell that is part of the immune system. Histiocytomas are most often found in younger dogs.

A histiocytoma appears as a bright red and hairless growth most often on the ears, head or limbs. A histiocytoma can form suddenly and will often be ulcerated. A histiocytoma will generally not be painful to your dog.

It is not known why or how your dog may develop a histiocytoma.

A physical examination with a biopsy or cytology is required to diagnose a histiocytoma.

A histiocytoma will often disappear without treatment in a few months. Topical antibiotics or steroids may be used to speed the healing. If the histiocytoma does not resolve either on its own or after a course of topical medications, it can be surgically removed.

There is no prevention for a histiocytoma.

No, you cannot develop a histiocytoma from your dog.