A bald spot is a sign, not a diagnosis. Something is either making your cat pull the hair out, usually by licking, or making the hair fall out on its own, and the fix depends on which one it is.
The most common story is itchy skin. The cat licks or scratches until the fur is gone, and flea allergy is the leading cause of that pattern, even in cats where you never see a flea. Other allergies, ringworm, mites, pain and, less often, illness or stress are on the list too. Ringworm can spread to people, so round, scaly patches deserve a prompt vet visit.
Some thinning is normal, such as sparse hair on the top of the head in front of the ears. For other bald spots your vet finds the cause, and where the spot is and how it looks are the first clues.
Is it normal?
Some thin or bare skin is part of being a cat:
- In front of the ears. Sparse hair on the top of the head in front of the ears is a normal variant in cats of any breed, according to veterinary dermatologists at Texas A&M.
- Ear flaps of older Siamese cats. Thinning hair on the ear flaps of aging Siamese cats is another normal variant.
- Hairless breeds. A Sphynx was born that way.
Normal shedding is different: fur on the sofa is expected, but the coat should still look even. Obvious bald patches or symmetrical thin areas are not normal shedding.
If a "normal" thin area changes, spreads, or turns red, scaly or itchy, it is no longer in the normal column.
Licked off or falling out?
Cats are secret groomers. Many cats hide their itching and lick when nobody is watching. Clues that your cat is overgrooming:
- You catch them licking, chewing or pulling at one area, or scratching more than usual.
- More hairballs than normal.
- The bare skin looks mostly normal, and the patches sit where a cat's tongue reaches easily: the belly, inner and back of the thighs, flanks, sides of the chest and base of the tail.
Hair falling out on its own looks different: the hair comes out from the root, often without much itch at first.
What you notice | What it suggests |
|---|---|
Stubbly, broken-off hairs where the cat can reach, more licking or hairballs | Overgrooming, usually because the skin itches (sometimes pain) |
Round, scaly or crusty patches with broken hairs on the face, ear tips, tail or feet | Ringworm until proven otherwise |
Even thinning on both sides, no itch, in a cat that also seems unwell | Hair falling out because of an illness |
Heavy shedding after a cold or other respiratory infection | Hair loss after illness, which is common in cats |
You don't need to make the call yourself. Vets pluck a few hairs and look at them under a microscope: hairs broken off at the tip point to itching and overgrooming, while hairs shed from the follicle point elsewhere.
Where the bald spot is tells you a lot
The location narrows the list. It doesn't replace the exam, but it helps your vet decide which tests come first.
- Back, base of the tail, groin, head and neck. Typical for flea allergy. Look for flea dirt there.
- Belly, inner thighs, flanks and sides, often on both sides. The classic overgrooming pattern. Usually itch from fleas or other allergies; stress comes into it only after those are ruled out.
- Ears, head and neck, with crusts or scratching. Allergies (food or environmental) and some mites, including feline scabies mites.
- Round, scaly patches on the face, ear tips, tail or feet. Think ringworm, especially in a kitten.
- Top of the head in front of the ears, smooth and unchanged. Normal.
- Thin, shiny skin and hair that comes away easily, on both sides, in a cat that is losing weight. Rare, but a vet visit soon.
Common causes of bald spots in cats
Fleas and flea allergy
Flea allergy is the most common cause of the symmetrical bald patches vets see in cats. Some cats react to the saliva in a single bite, and a very allergic cat may groom so thoroughly that you never see a flea. Indoor cats get fleas too: they come in on people and other pets.
Check for flea dirt: comb the coat over a damp white paper towel. Black specks that dissolve into reddish-brown smudges are flea dirt. Our post on flea allergy dermatitis explains the allergy. If your cat also has lots of tiny crusty bumps along the back, read our guide to miliary dermatitis, the same allergy showing up as scabs.
Because fleas are so easy to miss, vets often start with a flea control trial on every pet in the home.
Food and environmental allergies
Cats can be allergic to food proteins and to things in the environment such as pollen, dust mites and molds. Allergic cats tend to itch on the head and neck, get small crusty bumps, or lick symmetrical patches on the belly and legs. More on the basics in our guide to allergies in pets.
No blood or skin test reliably diagnoses food allergy in cats. The only way to find out is a food trial your vet sets up. Don't starve a cat onto a new diet: a cat that stops eating for long can develop serious liver problems.
Ringworm
Ringworm is a fungal infection, not a worm. It causes bald, scaly, crusted patches with broken hairs, most often on the face, ear tips, tail and feet, and kittens are the most likely to get it. It often infects people and spreads to other pets. Our post on ringworm in cats covers what treatment and cleanup involve.
Mites
Several mites cause hair loss in cats, and all forms of mange are highly contagious:
- Feline scabies mites (Notoedres): rare; crusts and hair loss start on the ears, head and neck.
- *Demodex gatoi*: more common in younger cats, contagious and often very itchy.
- Ear mites: head shaking, scratching at the ears and dark ear debris. See our post on ear mites.
- Walking dandruff mites (Cheyletiella): flaky skin along the back. Our cat dandruff post covers them.
Mange in cats goes deeper.
Pain
Pain can drive overgrooming too. Veterinary behaviorists list nerve pain alongside itch as a reason for excessive grooming, which is one more reason vets look past the skin.
Stress
Stress can cause overgrooming. Moves, new pets, loud noises and changes in routine can upset a cat, and some cats groom when anxious. Vets call the resulting hair loss psychogenic alopecia.
But vets rule out itchy causes such as fleas and allergies first, because stress is a diagnosis of exclusion. In a study of 21 cats referred with presumed psychogenic alopecia, 16 turned out to have a medical cause of itching, most often a food reaction, and only 2 had stress-related hair loss alone. The authors concluded that psychogenic alopecia is overdiagnosed. It was a small study, but a Texas A&M veterinary dermatologist makes the same point: overgrooming most often has a medical reason, usually itch or possibly pain.
So if someone tells you "it's just stress", ask what was done to rule out fleas and allergies.
Illness and hormones
Some causes start inside the cat. These usually don't itch at first:
- Hyperthyroidism can leave the coat unkempt, matted or greasy, alongside weight loss despite a big appetite and more thirst. A blood test checks for it.
- Cushing's disease is rare in cats. Affected cats are usually middle-aged or older, often have diabetes that is hard to control, and can have thin, very fragile skin and patchy hair loss.
- Rare cancers of the pancreas or bile ducts can cause spreading, symmetrical hair loss that doesn't itch, with shiny, thin skin and hair that comes out easily, in a cat that is losing weight and eating less.
- Heavy hair loss is common in cats after a respiratory infection.
- A tight collar or harness can rub the fur away.
A myth to drop: "feline endocrine alopecia" is no longer recognized as a disease. Symmetrical hair loss in cats has an underlying cause, and the most common one is flea allergy.
Can it spread to people or other pets?
Some causes can:
- Ringworm spreads to people through contact with an infected pet, and through shared bedding and brushes. Wash your hands after handling the cat and see your own doctor if you get a rash.
- Mites spread between cats and other pets, and walking dandruff mites can affect people too.
- Fleas move between every pet in the house, which is why vets treat all of them.
Allergies, pain, stress and hormonal problems don't spread.
What your vet will do
Expect questions before tests:
- When did it start, and which came first: the itching or the bald spots?
- Are other pets or people in the home itchy or getting rashes?
- What flea control does every pet get, and what does the cat eat? Any weight loss, thirst or appetite change?
Then the exam and tests chosen for your cat, which may include:
- Combing for fleas, flea dirt and mites.
- Looking at plucked hairs, skin scrapings and tape samples under the microscope.
- A fungal culture or an ultraviolet lamp check for ringworm. A culture can take up to three weeks.
- A flea control trial for every pet, and a food trial if allergy is suspected.
- Blood and urine tests when an illness or hormonal problem is possible.
- A skin biopsy if the first tests don't explain it.
Treatment depends on the cause, and your vet chooses the products. Because the workup can take a few weeks, many vets also ease the itch in the meantime. Environmental allergies are usually managed long term rather than cured.
While you wait for the appointment
Safe things you can do:
- Take photos of the patches today, so you and your vet can see whether they spread.
- Do the paper towel flea dirt check and tell your vet what you find.
- If the patches are round and scaly, limit cuddling, keep the cat off your bed and wash your hands after handling them until ringworm is ruled out.
- Keep routines steady and offer play, toys, window perches and quiet places to retreat.
Skip the home remedies
- No essential oils, tea tree oil included. Concentrated oils should never go on pets, cats are especially sensitive, and they lick it off.
- No dog flea products on a cat. Some dog spot-ons contain insecticides that are toxic to cats. The FDA's rule is simple: if the product is for dogs, don't use it on cats.
- No human creams, insecticides or medicated shampoos unless your vet chose them. Cats lick off whatever goes on the coat, and some insecticides are poisonous to cats.
If your cat drools, vomits, wobbles or trembles after a flea product or an oil, call your vet now.
Will the hair grow back?
Often, yes, once the cause is found and treated. Hair grows back after ringworm clears, for example. It takes time, so expect the coat to look patchy for a while after the itch stops.
Hair won't fill in where thin hair is normal for the cat (in front of the ears, a Sphynx), and the hair loss linked to rare cancers rarely resolves.
When to call your vet
Call now
- Drooling, vomiting, wobbling or trembling after a flea product, an oil or a dog product.
- Open, bleeding or infected-looking sores, or a cat that is weak, not eating or hiding.
See your vet soon (within days)
- Any new bald patch that spreads, is red, scaly, crusty or sore.
- Round, scaly patches, especially in a kitten or a new cat, or itchy people or pets at home.
- Constant licking, scratching or more hairballs than usual.
- Hair loss with weight loss, more thirst, a change in appetite or a greasy, unkempt coat.
Mention at your next visit
- Thin hair in front of the ears or on the ear flaps of an older Siamese that hasn't changed, in a cat that is otherwise well.
Quick answers
Is my cat overgrooming because of stress? It can be, but vets rule out itchy causes such as fleas and allergies first, and those turn out to be the reason more often.
Why is only my cat's belly bald? The belly and inner thighs are easy for a cat to lick, so that is where overgrooming shows first. Itch from fleas or allergies is the usual driver.
My cat has no fleas. Can it still be flea allergy? Yes. Allergic cats often groom the fleas away, so not seeing any doesn't rule it out.
Originally written by Diana Wells. Updated by the I Love Veterinary editorial team.
Sources
- Merck Veterinary Manual: Hair Loss (Alopecia) in Cats
- Merck Veterinary Manual: Dermatological Problems in Animals
- Merck Veterinary Manual: Feline Atopic Skin Syndrome
- Merck Veterinary Manual: Flea Allergy Dermatitis in Dogs and Cats
- Merck Veterinary Manual: Fleas of Cats
- Merck Veterinary Manual: Allergies of Cats
- Merck Veterinary Manual: Ringworm (Dermatophytosis) in Cats
- Merck Veterinary Manual: Mite Infestation (Mange, Acariasis, Scabies) of Cats
- Merck Veterinary Manual: Behavior Problems of Cats
- Merck Veterinary Manual: Disorders of the Pituitary Gland in Cats
- Merck Veterinary Manual: Cutaneous Paraneoplastic Syndromes in Small Animals
- Merck Veterinary Manual: Diagnosis of Skin Diseases in Small Animals
- Merck Veterinary Manual: Toxicoses From Essential Oils in Animals
- Waisglass SE et al. Underlying medical conditions in cats with presumptive psychogenic alopecia. JAVMA, 2006
- Texas A&M College of Veterinary Medicine: A Thin Line: Normal Shedding vs. Feline Alopecia
- Cornell Feline Health Center: Hyperthyroidism in Cats
- CDC: Ringworm Causes
- FDA: Safe Use of Flea and Tick Products in Pets
- EPA: Evaluation of Pet Spot-on Products
This article is for general information and is not a substitute for advice from your veterinarian.
