Why Is My Guinea Pig Losing Hair?

Dr. Joe Alcorn, M.S., D.V.M.

Dr. Joe Alcorn is founder of Care Animal Hospital in Temecula, California. He has a Bachelor of Science in Biology and Doctor of Veterinary Medicine from Colorado State University. He is a member of the American Veterinary Medical Association and his advice has been featured in large publications like Bustle and Martha Steward.

Home » Blog » Why Is My Guinea Pig Losing Hair?

Why is my guinea pig losing hair? You may be wondering this since despite having a care routine, fur still falls out of your pet. There are several potential causes of why guinea pigs suffer from hair loss and what you can do to treat it.

Why Is My Guinea Pig Losing Hair?

Infection is among the common causes of hair loss in guinea pigs, which may come from parasites, fungi, and abscesses. Natural shedding, barbering, war wounds, and abrasions can also make guinea pigs lose hair. Other possible reasons include pregnancy, ovarian cysts, drooling, metabolic problems, and skin illnesses.

The hair is a guinea pig’s protection against temperature changes and pressure. Particularly when your pet has long, fluffy fur, losing hair at an irregular rate may mean some health problems. 

Guinea pig eating an orange peel

Natural and Hormonal Causes

Guinea pigs lose hair naturally due to shedding, slobbers, and pregnancy. These are usually not cause for alarm, and you can help your pet overcome the situation.

  • Shedding: Guinea pigs naturally have a lot of hair. Long-haired ones tend to shed more than short-haired guinea pigs. Your pet may shed more than normal, typically during the springtime, because this is its way of removing spare fur to keep the body cool in the summer.
  • Slobbers: When a guinea pig overeats and drools, the hair below the jaw and neck gets wet from the dripping saliva. This is also due to the overgrowth of molars and premolars that trap the tongue.
  • Pregnancy: Pregnant guinea pigs may experience thinning hair due to lactation, especially in the last stages of pregnancy.

Abrasions and Barbering

If you notice that the hair isn’t falling out at the root, the problem may be self-inflicted. Guinea pigs tend to “barber” themselves as a reaction to stress, tooth pain, or arthritis. 

In some cases, the barbering may be due to boredom in the cage when guinea pigs start to fight. Some pets barber each other to assert dominance, causing war wounds, abrasions, and hair loss. A particularly strong guinea pig can yank out hunks of hair.


Guinea pigs have sensitive skins, making them susceptible to skin infections that drive hair fall.

Guinea pig with noticeable hair loss
  • Parasite Infection: When guinea pigs get mite infestation, you may not notice it right away because they are difficult to see by the naked eye. A guinea pig may get mites from poor hygiene, unclean cage, and contact with another infested pet. Constant scratching would cause inflammation, hair loss, and bald spots.
  • Fungal infection: Ringworms can also cause bald spots and itchy skin. Your pet’s excessive scratching would inflict self-trauma on the affected skin, causing hair to fall.
  • Yersinia infection: This kind of infection comes from contaminated food and water. Common signs include lymph nodes in the neck or shoulder, diarrhea, and open wounds. The bacteria can enter the wounds on the skin, causing hair loss.
  • Abscesses: This infection enters through a pet’s mouth or skin. Abscessed create blemishes on top of the skin that swell into capsule forms. These blemishes would target the hair, causing the fur in that region to fall at an abnormal rate. 

Other Health Conditions

Guinea pigs are susceptible to diseases, and thinning or losing hair is one of the most common symptoms.

  • Scurvy: Unlike other animals, guinea pigs can’t synthesize their own vitamin C. Without enough vitamin C in their diet, the deficiency would cause rough hair coat, hair loss, lethargy, and joint swelling.
  • Ovarian Cysts: Cysts cause abdominal swelling that can make fur fall. The excess androgen in a guinea pig’s body causes alopecia or a patchy pattern of hair loss. 
  • Pododermatitis: The footpad of guinea pigs may get inflamed and develop sores due to rough or abrasive flooring. The pressure on the skin’s soft tissues causes inflammation. When your pet sleeps or tries to walk on one side only, secondary bacterial infection irritates that side of the body, causing hair loss.
  • Greasy Seborrhea: Guinea pigs use their greasy glands to mark territories. However, it’s more common for male guinea pigs to have excess secretion of the glands. The discharge leaves gunk that can temper the skin, leading to hair loss.

How to Treat Guinea Pig Hair Loss

When a guinea pig loses hair, it’s typically an apparent sign of dermatological disease and other underlying illnesses such as sneezing. In such cases, our clinic can provide medicated shampoos or antifungal medication for more severe infections. I can also prescribe vitamin and mineral supplements.

Wet guinea pig
  • Antifungal medication: Guinea pigs are more sensitive to antibiotics than other pets. It’s crucial that a veterinarian prescribes the antifungal cream or oral medication.
  • Lifestyle change: I recommend changing lifestyle and nutrition for metabolic problems, especially scurvy. If your pet is losing hair due to barbering, I advise separating guinea pigs for a while to reduce hierarchical behavior.
  • Zinc supplements and vitamins: Female guinea pigs suffering from hormonal imbalance and losing hair can take zinc supplements to prevent further hair loss.
  • Ovariohysterectomy: This is a surgical procedure that removes the ovaries and uterus to eliminate ovarian cysts. Hormonal therapy may also reinforce this treatment.
  • Teeth realignment: it can be important to conduct dental X-rays and realignment for uneven wear of teeth and drooling.

What Are Common Breeds of Guinea Pigs?

The American and Teddy guinea pigs are common breeds with short, easy-to-maintain coats. Meanwhile, the Peruvian and Silki guinea pigs have long coats that require frequent brushing and more maintenance. Abyssinians and American guinea pigs are among the best for first-time owners.

Do Guinea Pigs Bite?

Guinea pigs don’t often bite as they are not aggressive by nature, although they do tend to nibble. If they bite, it’s possible that your pet feels threatened, frightened, uncertain, or bullied. Another reason is that it felt pain from your touch.


Guinea pigs are exotic pets that require special care, especially for the fur. However, natural shedding, hormonal imbalances, infections, skin illnesses, and abrasions may cause them to lose hair. Should conditions like these persist, it’s best to take your pet to the clinic for a wellness checkup and proper medication.