Dog Has Bumps Turning Into Scabs. The vet determined through shaving and cleaning the infected area on his head, and taking some cells from the bumps, that he has an allergic reaction to something. It has also been seen that often shampoo residue is the reason for dog black scabs, rashes, red bumps or itchy skin.
Superficial bacterial folliculitis is an infection that causes sores, bumps, and scabs on the skin. Insect bites, like from fleas or ear mites; Elimination of the irritant and treatment of.