OCD or obsessive compulsive disorder is a normal action performed by a dog in a slightly disturbed and repetitive fashion. The most commonly observed obsessive-compulsive behaviors are spinning, tail chasing, self-mutilation, fly biting, circling, fence running, hair biting, eating non-food substances such as dirt, rocks or feces, pacing, staring, and vocalizing and sometimes even aggression.
The behavior is not limited to any breed, gender or age of dog, although the specific type of OCD displayed may be affected by breed, such as spinning is seen in smaller dogs as opposed to self-mutilation. OCD usually begins around 1 to 2 years of age. The behavior intensifies over time and cannot be interrupted even with physical restraint, increases in frequency or duration, and interferes with normal functioning