Maladaptive behaviors: Stereotypical behavior; hair pulling-and-eating and alopecia (hair loss); self-injurious biting (2007)

LAREF [Laboratory Animal Refinement and Enrichment Forum]

Abstract

Animals kept in legally minimum-sized, unstructured enclosures very often exhibit stereotypical behaviors. Traditionally, these repetitive movement patterns without obvious goals or functions are categorized as abnormal. A healthy animal kept in a small, barren enclosure has little choice of expressing his or her biologically inherent drive to engage in species-typical behaviors, other than pacing back and forth, running in circles, somersaulting, rocking, self-biting, bar-biting, wood-gnawing, ear-pulling, hair-pulling, eye-poking and other bizarre activity patterns. There is nothing really abnormal, except the abnormally restrictive and abnormally boring housing conditions that induce the stereotyped expression of these activities.Hair pulling-and-eating reflects maladjustment to a distressing condition in mice. The inherent constraints of permanent confinement makes it very difficult to cure affected animals from this behavioral pathology. In rabbits and guinea pigs, hair pulling-and-eating is associated with a lack of fibrous foodstuff. A generous daily provision of hay or straw is probably the easiest way to prevent this behavioral disorder from developing in these two species.Self-injurious biting is a serious behavioral pathology that reflects gross insufficiencies in the rearing, housing and care of an animal. When I worked in small animal veterinary practices, I saw several dogs biting their feet repeatedly. Large dogs who do not get enough exercise, can end up chewing on their hind extremities to such an extent as to expose the bone. Cats who are kept strictly indoors also engage in self-injurious biting. They attack their tails. I remember several cases that required tail amputation.