Guinea Pig Hair Loss

Guinea Pig Hair Loss

Although there are many reasons for guinea pig hair loss the most common reason by far is due to Microscopic Mange Mites, a Painful Parasitic condition which can be treated with Ivermectin. Fungal Infections would be the next close runner up.

Old Age does not cause Hair Loss.

Any Hair Loss in an older Guinea Pig needs close investigation for its cause.

Check over this list for possible causes of Hair Loss :-


 Natural Hair Loss  Naturally Occurring (i.e. Bald Spots behind Ears)
• Shedding Hair
Mechanical Hair Loss Barbering “Hair Cutting” by another Artistic, Jealous or bored pig.

  • War Wounds and Abrasion and other Mechanical Hair Loss.
Parasites  Extremely Common Treat any Guinea Pig with suspected Mange Mites with Ivermectin
Fungus  Often starts on the face can be easily treated with a anti-fungus cream
Metabolic Hair Loss Vitamin C Deficiency, this can be hard to identify, Symptoms may suggest illnesses and a deficiency may also compound other problems

  • Postpartum and Hormonal hair loss, usually bilaterally symmetric. It is also important to note that stress of birth may lead to an infection of mites.
  • Bacterial Infection Cryptococcosis or Staphylococcal Dermatitis lesions and associated hair loss, usually occurring on the trunk.
  • Low Protein Diets Under 15% CP
  • Animal Near Weaning Age. Thinning of hair is usually observed in young animals at the time of weaning and is also associated with loss of baby fur and appearance of more coarse guard hairs.


Bald Spots Behind The Ears

The new Guinea Pig owner, after reading information about Hair Loss commonly caused by Either Mites, Lice and Fungus Diseases, will hurriedly run over to check their own Pig and be shocked to find large fur less areas behind there cavies ears.


Long Haired Guinea Pigs tend to shed more than Short Hair ones. While this maybe normal and some Guinea Pigs shed excessively, it is important to note that Shedding may also be one of the early signs of a Parasite or Fungal infection. Watch for general thinning of the Coat, Excessive Scratching, Sores, Dandruff or other possible indications your Pig may need treatment.


Although they may have all the Hay they want, no lack of nutrients, and ample space to move about, some Guinea Pigs are bound and Determined to chew on the hair of their cage mates. Apart from Isolating the industrious Guinea Pig, there is little that be done to curb this Behaviour.

War Wounds, Abrasions, And Miscellaneous Mechanical Hair Loss

A few Guinea Pigs are fighters, not lovers and Skirmishes may result in hunks of hair being yanked out of some unfortunate cavy’s pelt by a more aggressive one. Some owners will try and let them sort it out amongst themselves and only separating them if one is being Victimised. In some cases it has been found that two males is normally caused by a dominance issue.

“Through personal experience I have found giving each Cavy a food bowl each does tend to help this situation in some cases. (How would you like to have your dinner plate Invaded by somebody else on a day to day basis). It may also be worth providing separate houses as well. Before separating your cavies please give this little test a trial to see if there is an improvement. You may have to do the same with Hay Mangers also.”

Hormonal Causes

Hormonal & Lactation

When associated with Pregnancy and Lactation or an Ovarian Cysts, these will generally be Bilaterally Symmetric. Intensively bred sows especially in the last trimester may experience thinning and loss of hair. Repeated breeding will result in increasing loss of hair during Pregnancy and Lactation. It is thought to be caused by reduced anabolism of maternal skin associated with the rapid increase in Foetal Growth.

Cushing’s Disease

Cushing’s Disease is where a Guinea Pigs Adrenal Glands are enlarged producing to many hormones which interferes with normal hair growth. If your vet has eliminated all other possible causes an Ultrasound of the Adrenal Gland may show a possible enlargement. A daily dose of L-deprenyl may Help. If your vet is going to do an ultrasound to check for this you may want to take another cavy around the same weight and dimensions for comparison. The average size of the Adrenal Gland is between 3 to 4mm in Diameter.

Ovarian Cysts

Hormonal changes in sows that develop Ovarian Cysts can cause hair loss, usually appearing on the sides.