Healthy guinea pigs have soft, full coats, so hair loss in a guinea pig is a good indication that something is wrong. Most causes of hair loss in guinea pigs are treatable, so that soft coat can return with a little intervention.
When to Call
While some causes of guinea pig hair loss are natural and not a cause for concern, others indicate a health problem is present, so guinea pig owners should contact a veterinarian at the first sign of hair loss to rule out an infection or parasite.
Guinea pigs will sometimes chew the hair of other guinea pigs in the habitat, even when there is plenty of stimulation and room in the environment, and some guinea pigs will even self-barber. You can cure barbering by spraying bitter spray on the affected area to ward off the chewing.
Pregnant or lactating guinea pigs may struggle with hormonal hair loss, which typically rectifies itself when the hormones return to normal levels.
Infestations of skin parasites such as lice or mites cause most cases of guinea pig hair loss and need to be treated by a veterinarian.
Fungal infections, like ringworm, typically start on the face, creating spots of itchy hair loss that develop crusts or scabs. Antifungal creams and shampoos will kill the fungus and stop the hair loss.
Some bacterial skin infections, including cryptococcosis or staphylococcal dermatitis, cause hair loss on the animal's trunk and require medical intervention in the form of antibiotics.