Animal Models of Obsessive-Compulsive Behavior: A Neurobiological and Ethological Perspective

Animal models of obsessive-compulsive disorder (OCD) either may be induced in a laboratory setting or may arise spontaneously in veterinary patients. Both models have their usefulness and may replicate some or a constellation of signs associated with the human disorder. Classical laboratory models of OCD are induced by behavioral or pharmacological means. They include rat pup isolation distress calls, conjunctive behaviors, including polydypsia and increased gnawing, spontaneous alternation, and displacement grooming (Dodman & Olivier, 1996). Spontaneously occurring repetitive behavior problems in domestic animals were originally described as stereotypies before a link with human OCD was suggested. The first inkling of this connection surfaced when Goldberger and Rapoport (1991) described the successful treatment with clomipramine of acral lick dermatitis (ALD) in dogs. Their findings were subsequently confirmed in a more comprehensive publication the following year (Rapoport, Ryland, & Kriete, 1992), which represents a landmark in understanding the parallels that exist between canine ALD and a classical form of human OCD, specifically, hand washing. Both conditions involve extreme, apparently irrational assiduousness regarding personal hygiene and involve excessive repetition of selfcleansing behavior. Both conditions may lead to minor degrees of self-injury; both may affect normal behavioral agendas and social relationships; and both respond similarly to serotonin-enhancing pharmacological strategies. The veterinary community became excited about this diagnosis, which offered a new therapeutic approach to a formerly inexplicable and refractory condition.