What Causes Extreme Itching and Crusty Bumps on Top of a Dog’s Tail?

Intense itching with crusty bumps along the top of the tail, especially near the base, is a classic pattern for flea allergy dermatitis. Even a dog with only a few fleas can react strongly to their bites, and the scratching and chewing pull out hair and can lead to a skin infection.

Other causes to rule out include environmental or food allergies, anal gland problems, a bacterial skin infection and, less often, sarcoptic mange, which usually starts on the ear edges, elbows and belly.

Look closely for fleas or flea dirt, and start a vet-recommended flea preventive for every pet in the home, since treating only one animal often doesn't solve the problem. Because he's pulling out hair and the skin is crusting, a vet visit is a good idea. Your vet can check for mites and infection and give him something to ease the itch while the flea control takes effect. Read more about itchy skin and the signs of mange.

This is general information, not a diagnosis. Please follow your own vet's advice.