Pink, Mole-Like Bump on a Dog's Forehead
by danielle
(Plattsburgh New York)
Pink, hairless bumps on the head are common in young dogs as histiocytomas, which often go away on their own. In Boxer and pit bull mixes, mast cell tumors are also common and can look similar.
Because he's scratching it and making it bleed, have your vet look at it and do a needle test. A cone can stop him scratching meanwhile.
See lumps and bumps on dogs and mast cell tumors in dogs.
This is general information, not a diagnosis. Please follow your own vet's advice.