Why do cats lose their hair? A veterinarian explains the causes and countermeasures in detail.

The period from autumn to winter coincides with the molting season, which can be a source of frustration for cat owners. As opportunities for brushing increase, many people discover skin problems and visit veterinary clinics. Among these, hair loss is a common issue seen in the examination room.

In this article, we will explain the causes of hair loss in cats and how to deal with them.

What are the causes of hair loss in cats?

First of all, hair loss refers to areas where hair is meant to grow becoming thin or falling out, either partially or completely. Hair loss can occur due to skin problems like inflammation, or it can happen even when the skin itself is healthy.

Possible causes of hair loss include infectious diseases, external parasites, allergies, autoimmune diseases, tumors, psychogenic factors, and hormonal issues.

Infectious diseases

Infections by bacteria or fungi (yeast/mold) cause skin inflammation and subsequent hair loss. It can be accompanied by itching and eczema. Fungal-related hair loss often appears in circular patches with red, irritated perimeters, commonly known as ringworm. Fungal infections, in particular, can spread to other cats and even humans.

External parasites

Infestations of fleas or mites cause dermatitis, leading to hair loss.

Notoedric mange mites can infest the face and the edges of the ears, causing scabs and hair loss. This is also accompanied by intense itching.

When fleas infest a cat, the animal reacts to the flea saliva, triggering an allergic reaction. This leads to severe itching, inflammation, dermatitis, and hair loss.

Allergies

As mentioned with flea allergy dermatitis, allergies occur when the body reacts to specific proteins, causing itching and inflammation.

In the case of food allergies, cats may experience itching around the eyes and ears after consuming certain foods, which can lead to hair loss.

Cats can also develop atopic dermatitis. This is triggered by exposure to dust, pollen, or mites. It causes itching, redness, and hair loss on the face, paws, inner thighs, underarms, and lower abdomen.

Autoimmune diseases

Autoimmune diseases occur when the body produces antibodies that attack its own tissues.

Pemphigus is an autoimmune disease that affects a cat's skin, potentially causing erosions, blisters, and hair loss.

Tumors

If a tumor causes pain, the cat may lick the area until hair loss occurs.

Additionally, if white cats are exposed to direct sunlight for long periods, they may develop solar dermatitis on areas with thin skin, such as the ears, leading to hair loss. Cats over 6 years old with photosensitivity are at higher risk of developing a skin cancer called squamous cell carcinoma. This can occur not only on the ears but also around the mouth.

Psychogenic factors

When cats feel anxious or stressed, they groom themselves to calm down. In cases of psychogenic hair loss, the cat repeatedly licks the same area, causing hair to fall out. A characteristic sign of this is not just licking, but biting off the hair, resulting in broken hairs.

Hormonal factors

While less common in cats, hormonal imbalances—either excessive or insufficient hormone levels—can lead to symmetrical hair loss. Neutered or spayed cats may experience hair loss due to a deficiency in sex hormones. Although rare, hormonal conditions such as Cushing's syndrome or hypothyroidism can also cause hair loss.

Other causes

Cats that wear collars may experience hair loss in the collar area. This is thought to be caused by friction from the collar breaking the hair, or dermatitis resulting from the material of the collar.

How to deal with cat hair loss

Measures to address hair loss depend on the underlying cause. If the hair loss is caused by a medical condition, treatment is essential, so you must have your cat diagnosed at a veterinary clinic.

Flea and mite control

If the hair loss is due to fleas or mites, using parasiticides will lead to improvement. Some treatments can even eliminate mange mites. Over-the-counter products are often ineffective, so please consult a vet to get a proper diagnosis and the correct medication.

Drug therapy

For hair loss caused by infectious diseases, antibiotics or antifungal drugs are used. For allergies and autoimmune diseases, oral steroids or topical ointments are typically prescribed. Hormonal disorders are managed by hormone replacement or treatments to suppress production.

These are prescribed after a thorough diagnosis at a veterinary clinic. Even if the hair loss subsides, do not stop the medication on your own unless instructed by your veterinarian.

Reducing stress

In cases of psychogenic hair loss, the cat is experiencing some form of stress in their daily life. In multi-cat households, conflict with a housemate can be a source of stress; you may need to arrange your home to allow the cats to keep their distance.

Litter box issues can also trigger psychogenic hair loss. Try changing the type of box, increasing the number of boxes, switching the litter, or changing the location to ensure the cat feels secure while using the facilities.

If your cat spends a long time alone, they may lick themselves out of boredom, so it is important to keep them occupied.

For psychogenic hair loss, anti-anxiety medication or supplements may sometimes be used. As a home-based measure, try setting out several toys for when you are away. It is important to use items that are hard to swallow, and try rotating their locations. Hanging toys rather than placing them on the floor can keep a cat entertained for longer.

Increasing communication is also considered important. You might wonder if cats can learn tricks—the answer is yes. Using treats to teach tricks like "high five" can be an enjoyable training experience for both the cat and the owner.

Preventing direct sun exposure

In white cats, excessive sun exposure can cause solar dermatitis, which often progresses to tumors. Therefore, try to limit exposure to direct sunlight.

If a tumor develops, treatment such as surgical removal will be necessary.

Reconsidering the collar

If the hair loss is caused by a collar, reconsider its use. Switch to one that is smaller, made of a different material, or lighter in weight. If the collar is not strictly necessary, it might be best to remove it altogether.

Summary

Hair loss can stem from various causes, ranging from non-medical issues like collars to psychogenic factors or underlying diseases. If there are scabs, itching, or redness, there is a high possibility of an infectious disease; if the cat is repeatedly licking the same spot, it is likely psychogenic. If the hair loss is symmetrical, you should suspect hormonal issues. In any case, a proper diagnosis from a veterinary clinic is essential.

Do not dismiss hair loss—please consult your veterinarian.