Compulsive Behavior in Dogs
Dr. Alice Moon-Fanelli
Compulsive behaviors occur in most species, including humans and dogs. Such behaviors have been recognized in humans for some time, but appreciation of their occurrence in companion animals is relatively recent. Many of the repetitive behavior conditions that are seen in dogs have numerous and compelling similarities to obsessive compulsive disorders that occur in people. In addition, affected dogs often respond to the same type of medications used to treat human obsessive compulsive disorder. Compulsive behaviors in dogs are sequences of behavior that are repetitive and relatively invariant in expression and orientation. They do not appear to serve an obvious purpose and some are potentially injurious to the animal.
Owners of severely affected dogs report that their companion appears to be anxious or distraught. Affected dogs often engage in their compulsions rather than play or eat and are often unresponsive to their owner's affection or directions. Affected dogs lose aspects of good companionship.
Compulsive disorders appear to be related to normal innate (genetic or "hard-wired") behaviors like grooming, predatory behavior, eating, locomotion, or sexual behavior. Compulsive "grooming" disorders include repetitive licking of the lower extremities of the legs, which may cause lesions referred to as lick granulomata (a.k.a. acral lick dermatitis), and compulsive chewing of the feet or toe nails. Acral lick dermatitis (ALD) is most common in large (> 50lbs), active breeds that have been selected to work closely with people and form strong attachments. Not surprisingly, dogs with ALD may also have other anxiety-related behavior conditions such as separation anxiety, thunderstorm phobia, and fear-based territorial aggression.
Flank biting or sucking is thought to be related to "nursing behavior"; and tail chasing/spinning, shadow chasing and some forms of fly snapping may be related to predatory behavior. Tail chasing is most commonly observed in terriers and herding breeds, although any breed can be affected. Repetitive circling, fence running, digging and pacing are also common manifestations of compulsive behavior.
Sometimes a dog develops a compulsive disorder without exposure to an identifiable stressor. Such dogs are usually young (less than 1-1/2 years of age) and may have a family history of compulsive behavior.
That said, expression of compulsive behavior is often a manifestation of environmental anxiety or stress. Compulsive behaviors often develop in response to a specific situation but may become generalized to any situation in which the animal experiences conflict. Emotional conflict can arise from environmentally induced anxiety as well as inconsistent interactions between the owner and the dog. When a dog is repeatedly placed in a situation of conflict, the threshold for the performance of the repetitive behavior decreases so that the behavior may be eventually manifested when there is any increase in activity arousal. Eventually a dog with compulsive behavior loses control over the behavior. At this stage, the behavior will occur in non-stressful situations.
Conditions known to trigger anxiety in susceptible dogs include relatively benign experiences that would not have a negative impact on most dogs. Potential triggers for a susceptible dog include:
Inadequate social interaction with owners or conspecifics
Owners departures and returns
Environmental change (e.g. boarding at kennel)
Changes in social arrangement (introduction or departure of people or pets)
Particular sounds (storms, vacuums, yard machinery, telephones, microwave bells, running water)
Lack of mental and physical stimulation appropriate for the dog's breed and age
Some compulsive behavior may inadvertently become conditioned by reinforcement from well meaning owners. There is also some evidence that the development of compulsive behavior is facilitated by an inherited predisposition.
Some behaviorists believe that compulsive behaviors are the animal's way of coping with a stressful situation as the behavior is commonly seen when the animal is over- or under-stimulated. However, it has been suggested that once the behavior becomes "fixed", the pathways in the brain which control the behavior are sensitized, so that the animal follows the compulsive sequence of behaviors whenever it becomes anxious or even simply aroused. It may be more appropriate to think of compulsive behavior as a clinical manifestation of an environmentally-triggered nervous system disorder. It has been suggested that brain chemistry may be altered in affected animals.