Barbering refers to the abnormal grooming behavior of an animal chewing and tearing the fur and whiskers of either itself or another animal. Barbering is known to occur in most companion rodent species, including guinea pigs, rats, and mice. When one animal barbers another animal, it is used as a display of dominance, meaning that the more dominant member of the group chews on the fur and whiskers of the less dominant members. Barbering results in alopecia (loss of hair) in the affected areas. Such status conflicts most often occur between adults of the same sex or between adults and juveniles. Some rodents will barber themselves due to stress, inappropriate caging, boredom, and even heredity.
Barbering in guinea pigs
If a guinea pig is being barbered, the hair loss usually occurs in patches. Also, there may be visible bite marks and skin inflammation underneath the fur. If you do notice hair loss, it could be due to causes other than barbering. Hair loss can also be caused by genetic or health problems such as a vitamin C deficiency or a parasitic infection on the skin. Hair loss is common in female guinea pigs that have been used for breeding. Also, young guinea pigs that are weaning from their mothers may appear to have thinning hair. This is normal, as their coat is transitioning to a coarser adult coat. However, if their coat does not complete the transition and remains thin, there may not be enough protein in their diet.
Barbering in guinea pigs can be prevented in several ways. If barbering is being performed by more dominant group members, it is important to separate them from the animals they are barbering. Keeping stress levels to a minimum can help prevent a guinea pig from barbering itself. Stress can be minimized by keeping the guinea pig in a consistent, quiet environment. It is important to provide your guinea pig with a “house,” such as a small cardboard or wood box, inside its cage. This box gives it a sense of protection and also a place to sleep. You can also prevent barbering by weaning guinea pigs from their mothers early and feeding them long-stemmed hay. Long-stemmed hay provides fiber and is a healthy part of the diet. It also is a form of enrichment that will keep your pet occupied.
Barbering in rats and mice
Unlike guinea pigs, barbering in rats and mice does not affect the skin. The skin will appear normal, without any signs of irritation, inflammation, or cuts. The only sign is hair loss, with the animals chewing the hair so close to the skin that it appears clean-shaven.
If an animal is barbering itself, the most common places for hair loss are the stomach and front legs. If an animal is being barbered by another animal, the most common places are the muzzle, head, and shoulders.
As in guinea pigs, barbering in rats and mice can be caused by stress or boredom. It is important to keep your companion rat or mouse happy and active. Stress can be prevented by housing your pet in an appropriate-sized cage with objects and activities for enrichment, including objects for gnawing, tunnels, and an exercise wheel.
If you notice that your companion rodent is losing hair, it is important that a veterinarian examine it to be sure that there are no underlying health problems causing the hair loss. Once your veterinarian has ruled out health problems, you will be able to discuss with him or her your companion rodent’s living situation, including diet, cage mates, forms of enrichment, and housing. If it is discovered that the barbering is being done by another animal, it is best that the dominant animal be separated from the other(s). If the animal is self-barbering, your and your veterinarian will need to make changes to minimize this behavior. Often, barbering does not cause irritation or infection so the animal will not need to be placed on medications. If an animal is allowed to continue barbering, however, the animal’s condition could worsen and require medical treatment.
Lisa Karr-Lilienthal, Ph.D., and Kaycee Points - University of Nebraska-Lincoln