5. Why do dogs chase their tails?

Other than for grooming reasons (injury to tail or anal area as well as managing external parasites), it is abnormal for dogs to consistently chase their tails. It can occur as an attention-getting activity or can escalate to a compulsive behavior, in that the dog engages in the behavior with reduced ability to discontinue to the point where it interferes with normal activities. Compulsive behaviors are similar to obsessive compulsive disorders (OCDs) in people; one theory is that it results in increased endorphins in the brain, thus acting to reinforce pleasure for the behavior. —John Ciribassi, DVM, DACVB