Hair loss (alopecia) is something you see, not a disease in itself. Hair grows in cycles of growth, rest and shedding, and anything that upsets that cycle or damages the hair can leave thin or bald areas. In cats, the hair loss is usually secondary: the real problem is an infection, a parasite, an allergy, stress or, less often, an illness elsewhere in the body. [1] Treatment is aimed at that cause, not at the hair itself. [1]
Itchy cats and overgrooming are covered in itchy cat and overgrooming: common causes. This guide looks at the bigger picture: the main groups of causes, the hormonal, whole-body and inherited ones vets look for, and when shedding is normal. For dogs, see hair loss in dogs.
Born with it or acquired later
- Inherited hair loss is part of a cat’s genetic makeup. Some breeds have been bred for a hairless or sparse coat (see below). [5]
- Acquired hair loss starts in a cat that had a normal coat. Most cases in cats fall into this group, and the common causes are listed in the next section. [1]
The most common causes in cats
A 2026 review of hair loss across people, dogs and cats lists the leading causes in cats as ringworm, flea allergy and other itchy skin diseases, mites such as Demodex, overgrooming and illness elsewhere in the body. Hormonal and immune causes are much less common in cats than in dogs. [1]
Itchy skin disease. Very often a cat removes its own hair by licking and chewing because its skin itches. Flea allergy, food allergy, environmental allergy and skin parasites are the usual triggers. [1] Hair licked away on both sides of the body, or on the belly, is one of the typical ways flea allergy shows in cats, and this licked-off hair loss is one of the four common skin patterns of allergy in cats. [2] Because cats often lick rather than scratch, an itchy cat can look calm while it slowly grooms the hair away. [1][2]
Ringworm. This fungal infection lives in the hair and the outer skin. It can cause round or patchy hair loss with scaling, crusts, small bumps or redness, and the itch varies. Kittens, long-haired cats, cats in crowded or stressful homes and cats that are already unwell are more at risk, and some cats carry the fungus with few or no signs. [1] People can catch it from cats. See ringworm in dogs and cats, and for mites see mange in cats.
Stress-related overgrooming. Some cats groom so much that bald areas appear, often on the belly and inner thighs, even with no skin disease. This is thought to be a behavior problem that stress in the cat’s surroundings can set off. [3] Vets only call overgrooming stress-related after infections, parasites, allergies and other medical causes have been ruled out. [1][3]
Hormonal and whole-body causes
Hair loss from a hormone problem is much less common in cats than in dogs. [1]
- Hyperadrenocorticism (too much adrenal hormone, also called Cushing’s) is uncommon in cats. When it happens, it is linked to a poor coat, hair loss and very fragile skin, often together with diabetes that is hard to control. [1]
- Hidden cancer. Feline paraneoplastic alopecia is a rare hair loss tied to a tumor inside the body, most often of the pancreas or bile ducts. The hair loss is not itchy, spreads quickly and is even on both sides. It starts on the belly, neck, inner legs and around the tail, can spread to the face, and leaves skin that looks smooth and shiny. The back is usually spared, and some cats get scaly, cracked footpads. [4] Weight loss, poor appetite, vomiting, diarrhea or tiredness usually appear around the same time or soon after, and the outlook is poor. [4] See skin signs of internal cancer in cats.
- Fragile, tearing skin has also been reported as a rare skin sign of cancer in cats. [4]
A review of these skin signs advises vets to keep a hidden tumor in mind in middle-aged and older cats whose skin problem looks unusual. [4]
Inherited hair loss and hairless breeds
- The Sphynx has been bred for near hairlessness, and the curly coat of the Devon Rex is another breed trait. A 2010 study traced both to changes in the same hair gene, KRT71. [5]
- The study found no gene change behind several other hairless or curly coat types it tested, so not every inherited coat problem in cats has a known cause yet. [5]
If a kitten is born with missing hair or a young cat’s coat thins for no clear reason, ask your vet to check it.
Hair loss on the ears
Ear mites are a leading cause of outer ear inflammation in cats. Affected cats usually have very itchy ears, shake their heads and scratch, and can hurt the skin around the ears. Discharge, a lot of ear wax, redness and crusts on the ear flap are typical signs. [6] Hair loss on the ears and face can also be part of an allergy pattern [2] or of the rare cancer-linked hair loss above. [4] See ear mites and ear problems in cats.
Normal shedding or a problem?
New hair replaces old hair all the time, so some shedding is normal. In cats, how hair grows and sheds depends on the body area and on day length through the seasons. [1]
- Shedding that leaves bald spots, or thin hair on both sides of the body, is not normal shedding and needs a vet check. [1][2]
- Shedding with a full coat underneath is most likely the normal coat change.
What the signs can look like
Depending on the cause, hair loss in cats can come with: [1][2][4]
- redness
- scaling or greasy scale
- crusts and small bumps
- darker skin
- itching, or a lot of licking
- smooth, shiny skin with no itch
Yeast or bacteria can take hold on the damaged skin and make things worse. [2][4]
How vets find the cause
Your vet starts with the history and a full exam of the skin and the cat’s general health. [1][4] For ringworm, vets look at hairs under the microscope, use a special lamp where it helps, and run a fungal culture or a PCR test. [1] They also check for fleas and mites, and a skin sample (biopsy) may be needed. [3][4] For suspected food allergy, the only accurate test is a strict diet trial set up by your vet. [2] If an illness elsewhere in the body is suspected, further tests may follow. [4]
Treatment depends on the cause that is found. [1] Do not use human hair-regrowth products on your cat: one widely used ingredient can poison cats even through contact with the skin, including traces passed on from your hands or bedding. [1]
When to see your vet
- Bald patches, or hair loss on both sides of the body, rather than ordinary shedding. [1][2]
- Hair loss with redness, scaling, crusts or a change in skin color. [1][2]
- Skin that tears or breaks easily. [1][4]
- Fast, non-itchy hair loss with shiny skin, or with scaly, cracked footpads. [4]
- Hair loss together with weight loss, poor appetite, vomiting, diarrhea or tiredness. [4]
- A kitten or young cat whose coat is missing or thinning. [5]
FAQ
Why is my cat losing hair but not scratching?
Many cats remove hair by licking rather than scratching, so an itchy cat can look calm. [1][2] Some causes, such as the rare cancer-linked hair loss, are not itchy at all, [4] so have it checked.
Is hair loss on both sides of my cat’s body a hormone problem?
Usually not. In cats, even hair loss on both sides is most often licked off because of itchy skin, with flea allergy a common trigger. [1][2] Hormone causes are uncommon in cats. [1]
Can stress make my cat lose hair?
Yes, some cats overgroom when stressed, but vets rule out medical causes first. [1][3]
Will the hair grow back?
It depends on the cause, so finding it is the first step. [1]
The bottom line
Hair loss in cats is a sign, and treatment depends on finding its cause. [1] In cats it is most often linked to itchy skin disease such as flea allergy, ringworm, parasites or stress-related overgrooming. [1][2][3] Hormone causes are uncommon, but fragile skin or fast, shiny, non-itchy hair loss can point to illness inside the body. [1][4] The Sphynx and Devon Rex coats come from changes in a hair gene. [5]
This article is for general information and is not a substitute for a veterinary exam. If you are worried about your cat’s skin or coat, see your veterinarian.
Sources
- Seo J, Yun JH. Alopecia management from a comparative perspective: pharmacological and pharmaceutical insights in humans, dogs, and cats. Front Vet Sci. 2026;13:1907027. doi:10.3389/fvets.2026.1907027. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC13552210/
- Diesel A. Cutaneous Hypersensitivity Dermatoses in the Feline Patient: A Review of Allergic Skin Disease in Cats. Vet Sci. 2017;4(2):25. doi:10.3390/vetsci4020025. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC5606602/
- Griesser AC. Does treatment with clomipramine reduce cat psychogenic alopecia? Vet Evid. 2022;7(2). doi:10.18849/ve.v7i2.573. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC13011011/
- Guillén A, Hendricks A, Verbrugghe A, Rocchigiani G, Espadalé E. Cutaneous paraneoplastic syndromes in cats: a comparative clinical review. J Feline Med Surg. 2026;28(1):1098612X251407872. doi:10.1177/1098612X251407872. Open access (CC BY-NC 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC12855766/
- Gandolfi B, Outerbridge CA, Beresford LG, et al. The naked truth: Sphynx and Devon Rex cat breed mutations in KRT71. Mamm Genome. 2010;21(9-10):509-515. doi:10.1007/s00335-010-9290-6. Open access (CC BY-NC). https://pmc.ncbi.nlm.nih.gov/articles/PMC2974189/
- Perego R, Spada E, Avizzano C, Baggiani L, Proverbio D. Prevalence of Otitis Externa in a Population of Owned Cats in Northern Italy. Animals (Basel). 2026;16(5):706. doi:10.3390/ani16050706. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC12983938/