Cat losing hair: bald patches, over-grooming and when to see a vet

A cat losing hair is showing you a sign, not a diagnosis. Most hair loss in cats comes from something the cat is doing, like licking or pulling at itchy or sore skin, rather than hair simply falling out. It’s rarely an emergency, but every bald patch deserves a vet visit. If you’re not sure how fast to act, our should I go to the vet check can help.

Is my cat losing hair or just shedding?

Cats shed all the time. As new hair grows, old hair falls out, and some seasons bring heavier shedding. Merck Veterinary Manual says shedding is likely normal if there are no bald patches and no hair loss in a matching pattern on both sides of the body.

It’s time to look closer if you notice:

• Bald patches or areas where you can see skin through the fur
• Thin fur in a matching pattern on both sides of the body
• Red, scaly, crusty or darker skin where the hair is missing
• More licking, chewing or scratching than usual

How can I tell over-grooming from hair falling out?

Feel the patch. International Cat Care explains that when a cat pulls or licks hair out, the short hairs left behind feel spiky and sharp, like stubble. When hair falls out for other reasons, any hair left in the area feels soft and normal. Your vet may also look at hairs under a microscope to tell the two apart.

This matters because over-grooming points to itch, pain or stress, while true hair loss points to other problems, such as infection of the hair follicle or hormonal disease.

Many cats over-groom in secret. Merck notes that unlike dogs, many cats hide their itching, so you may never catch your cat in the act. Hairballs, fur in the litter box or hair around the house can be the only clues.

What causes bald patches in cats?

Merck says inflammatory causes, mainly itchy or painful skin, are the most common reason for hair loss in cats.

How do fleas and allergies cause hair loss?

Fleas are the top suspect. Merck says flea allergy dermatitis is the most common cause of hair loss on both sides of a cat’s body. Cats with flea allergy can also have a “racing stripe” of sore skin along the back. International Cat Care lists flea allergy as one of the most common causes of over-grooming.

You may never see a flea, because cats groom them off. Comb your cat over white paper and put any dark specks on damp paper towel. A reddish-brown smear means flea dirt. Our guide to fleas on cats covers treating your cat and your home.

Food and environmental allergies cause the same pattern of itch and over-grooming. Our guide to a cat scratching a lot explains how vets work out which allergy it is, including the food elimination trial.

Can pain or stress make a cat pull out its fur?

Yes. International Cat Care says cats with bladder pain, from conditions such as feline lower urinary tract disease, may lick the area over the pain. That often leaves a bald or thin patch on the lower belly, inner thighs and around the genitals. Cats with arthritis may lick over sore joints, and treating the joint pain helps.

Stress is part of many cases. International Cat Care says most over-grooming starts with a skin or pain problem but also has a stress component, and for a small number of cats stress is the only cause. Cats groom to calm themselves, and it can become compulsive. Some Oriental breeds seem more prone to stress-related fur pulling.

A male cat licking his genitals and straining in the litter box may have a urinary blockage, which is an emergency. See our guide to urinary blockage in male cats.

Is ringworm contagious to people?

Yes. Ringworm is a fungal infection of the skin, hair or claws, not a worm. Merck says about 98% of cases in cats are caused by the fungus Microsporum canis, which spreads easily and often infects people.

International Cat Care describes the common signs as roughly circular areas of hair loss, especially on the head, ears or legs. Merck adds scaly, crusted patches with broken hairs, most often on the face, ear tips, tail and feet. Some cats have mild signs or none at all, and ringworm can look a lot like flea allergy.

Kittens under a year old, longhaired cats and Persians are more likely to get it. International Cat Care says the spores can survive in the home for up to two years.

Your vet may use an ultraviolet lamp, look at hairs under a microscope or send a fungal culture, which is the most accurate test but can take up to three weeks. Treatment is usually a combination of medicine by mouth and treatments on the skin, plus thorough cleaning at home. Your vet sets the medicine and the dose for your cat.

To protect your family while your cat is treated:

• Wear disposable gloves when handling your cat, and wash your hands well afterwards
• Keep your cat in one easily cleaned room if you can
• Disinfect or throw out bedding, collars, toys and brushes
• Keep children from handling the cat until your vet says it’s safe
• See a doctor if you notice any skin changes

In a home with several cats, International Cat Care says all the cats usually need to be checked and treated.

Can hormonal problems cause hair loss in cats?

Sometimes, though they’re uncommon. Merck says hair loss from hormonal problems usually isn’t itchy at first, unless the skin also becomes infected.

• Too much adrenal hormone (hyperadrenocorticism): causes hair loss, darker skin and skin that becomes extremely fragile and tears easily.
• Low thyroid hormone (hypothyroidism): very rare in cats. It causes thin hair growth and dry, scaly, thickened skin.
• After spaying or neutering: mild hair loss near the genitals can occasionally happen and doesn’t seem to itch.

Merck also notes that significant hair loss is common in cats after a respiratory infection, and that a lack of protein in the diet can slow hair growth, though that’s uncommon on a complete cat food. If your vet suspects a whole-body problem, they may run blood and urine tests.

What will the vet do?

Merck describes the usual steps. Your vet will ask about your cat’s history, examine the skin and coat, and check for fleas and mites with combing and skin scrapings. They may test hair and skin for bacteria, yeast or ringworm. If those don’t give an answer, a skin biopsy or blood and urine tests may follow.

Because finding the cause can take time, your vet may give medicine to ease itch or discomfort in the meantime. Don’t use human creams or medicines on your cat unless your vet tells you to.

Before the visit, take clear photos of the bald patches. Our symptom photo check can help you describe what you see and decide how quickly to book.

How can I help at home?

• Keep every pet on flea control all year, using a product made for cats.
• Feel the bald patches for stubble and note where they are.
• Watch the litter box for straining, small puddles or blood.
• Reduce stress with a steady routine, and separate food, water and litter boxes for each cat.
• Don’t shave or treat patches yourself before your vet has seen them, especially if ringworm is possible.

Written by the CatsMed Team from the sources above. This guide isn’t reviewed by a veterinarian and isn’t a substitute for one. See how we research.