The most common reason dogs bite their tails is allergies. These allergies can be caused by fleas, diet and other environmental factors according to Vetinfo. The exact causes of allergies are not always identifiable, but there are many types of medication to relieve the symptoms. Bowel problems are another frequent cause of tail biting. read more
Tail-biting may be added to the list of behaviors suggesting anal gland problems. If your dog is biting the base of his tail and the nearby area, anal glands may be the root of the problem. This is another good reason why a vet visit is important when you notice tail-biting behaviors in dogs. read more
Dogs have been known to experience hair loss on their tails due to this kind of behavior and even cause themselves injury. What it boils down to is if you notice that your dog seems to be chasing after her tail an excessive amount, the best thing you can do for her health is to have her checked out by a veterinarian. read more