There are many reasons for hair loss to occur in guinea pigs. One of the common causes for hair loss is due to barbering, a behavior by which guinea pigs will chew or tear their own or each other's hair off as a result of conflicts between adult males or between adults and young. It may also be exhibited by females that are under stress.
The outward symptoms that are characteristic of this behavior are very short, chewed off hairs over an area that appears as a bald patch. The skin that has suffered the barbering may be inflamed, bruised, or may carry other signs of injury.
Barbering often occurs in relation to conflicts between adult males or between adults and juveniles.
Hair loss due to barbering is typically identifiable by the appearance of bite marks and skin inflammation along with the hair loss. However, because there are many possible causes for this condition, a differential diagnosis may be the best method for diagnosis. This process is guided by deeper inspection of the apparent outward symptoms, ruling out each of the more common causes until the correct disorder is settled upon and can be treated appropriately. You will need to provide your veterinarian with your guinea pig's dietary history and a description of the onset of symptoms so that your veterinarian can identify the underlying cause of the hair loss.
Besides self-barbering or barbering by other guinea pigs in the group, hair loss can also be caused by genetic problems, problems in metabolism, or due to dietary deficiencies. The hair loss may even be a natural progression of aging. Young guinea pigs that are weaning from their mothers will have a normal hair thinning as their coat changes from light infant fur to coarser adult fur. It is not necessary to treat this, but your veterinarian will want to make sure that the young are receiving sufficient amounts of protein in their diets.
The group of processes that involve the use of nutrients by the body
A disorder in which animals bite the fur of subordinate animals as a method of establishing dominance.