Barbering (hair chewing) can be carried out by a guinea pig on itself or on its companions and is a behaviour induced by various factors. Dominant subjects may chew the hair of subordinate animals. When self-inflicted (Fig. 1), it may be caused by stress, loneliness or boredom. The diagnosis is made on the basis of a lack of lesions of the skin, which appears undamaged, and of the fur, which seems to have been shaved off. Under microscopic observation the hairs appear to be cut, confirming the diagnosis (Fig. 2). The treatment is based on eliminating the cause. In the case of barbering due to dominance, the animals involved must be separated, but organized in groups such that no animal remains alone. In the case of self-inflicted lesions, attempts should be made to improve the care of the animal, for example by enriching its environment, increasing the available space, providing a companion or reducing stressful factors.
