Barbering (fur and Whisker Trimming) by Laboratory Mice As a Model of Human Trichotillomania and Obsessive-compulsive Spectrum Disorders

Animal diseases that develop spontaneously in a limited subpopulation can provide powerful models of human disease because they provide a means to investigate the interaction of a broad range of biological and environmental etiologic processes. In contrast, with experimentally induced animal models, the etiology of the model is inherently fixed, and can only speak to a limited subset of those involved in the human disease. 'Barbering' (abnormal whisker- and fur-plucking behavior) in mice resembles human trichotillomania (compulsive hair plucking) in that barbering mice pluck focused areas of hair, and engage in post-plucking manipulatory and oral behaviors. We performed a cross-sectional epidemiologic survey of a population of 2,950 laboratory mice to further assess the face validity of barbering as a spontaneous model of trichotillomania. Patterns of hair loss and demographic and etiologic risk factors were recorded for each mouse, and were analyzed by use of logistic regression. Barbering paralleled trichotillomania in terms of phenomenology, demography, and etiology. Thus, similar to trichotillomania, barbers predominately plucked hair from the scalp and around the eyes and the genitals; barbering was female biased, and had its onset during puberty; and etiologic factors included reproductive status and genetic background. Therefore, barbering has excellent face validity as a model of trichotillomania, and may represent a refined and non-invasive model, especially for studies of the complex genetic/environmental etiologies of this disorder.