Why Does My Cat Have Dandruff?

What it usually means

Dandruff is a build-up of dead skin cells that the coat would normally shed unseen. VCA describes a related condition, seborrhea, where the skin's oil glands produce too much or too little oil, leading to flaky, sometimes greasy or smelly skin, most often along the back, face and flanks. In most cats, VCA says seborrhea is secondary, meaning something else is driving it.

The most common drivers are reduced grooming, parasites and skin disease. Overweight cats, arthritic cats and older cats often cannot reach their lower back, so flakes pile up just in front of the tail. Fleas, mites such as Cheyletiella (sometimes called walking dandruff), and ringworm, a fungal infection, can all cause scaling. Allergies, bacterial or yeast infections, hyperthyroidism, diabetes and diets low in fatty acids are other causes. Some breeds, such as Persians, have an inherited form.

Signs to look for

Note where the flakes are and what they look like. Fine white flakes over the lower back of a heavy cat suggest a grooming problem. Flakes that seem to move, or appear with intense scratching, suggest mites or fleas. Circular patches of hair loss with scaling can be ringworm, which can spread to people and other pets.

Also look for greasy or matted fur, a rancid smell, redness, scabs, small bumps along the back and neck, or bald areas. A dull, unkempt coat in a cat that used to groom well often means the cat feels unwell or is in pain, which is a reason for a checkup on its own.

When to call your vet today

Book a visit soon if dandruff comes with itching, scratching or overgrooming, hair loss, scabs, sores, redness or a bad smell, or if it appeared suddenly. Call promptly if anyone in your home develops itchy red rings on their skin, which can be ringworm, and see your own doctor for yourself.

Call too if dandruff comes with weight loss, increased thirst or appetite, vomiting or a change in energy. VCA lists hyperthyroidism and other internal problems among the causes, and older cats in particular often show coat changes before more obvious signs. A cat that has stopped grooming completely needs to be seen.

When it's an emergency

Dandruff itself is not an emergency. Get your cat seen urgently if skin problems come with open, weeping wounds, rapidly spreading redness or swelling, a fever, or a cat that is lethargic and not eating. Sudden severe skin reactions can follow contact with certain chemicals or medicines.

If your cat shows tremors, twitching, drooling or wobbliness after a flea product was applied, especially a product made for dogs, treat it as an emergency. Wash nothing off without advice; call your vet or the nearest emergency vet now, and call ASPCA Animal Poison Control at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661 (a fee may apply).

What you can safely do at home

Gentle, regular brushing helps by spreading natural oils and removing loose flakes and hair; this is especially useful for overweight, senior and long-haired cats that cannot groom themselves fully. Run a humidifier in dry winter months and make sure fresh water is always available. Keep your cat's bedding clean.

Do not bathe your cat with human shampoo or dandruff shampoo, which can irritate cat skin and be harmful if licked off. VCA advises using only cat shampoos and rinsing thoroughly. Do not add oils or supplements to food without checking with your vet, and never use dog flea products on a cat. If your cat is overweight, ask your vet about a safe weight-loss plan.

What the vet will likely check

Your vet will look closely at the skin and coat, comb for fleas and flea dirt, and ask about diet, grooming, itching and other pets. VCA lists skin scrapings and hair plucks to look for mites, skin cytology to check for yeast and bacteria, and a fungal culture for ringworm.

If the cause is not obvious, blood tests can check for hyperthyroidism, diabetes and other internal illness, and a skin biopsy may be needed in some cases. Treatment depends on the cause: parasite control, treating infections, managing allergies, adjusting the diet, medicated cat shampoos, pain relief for an arthritic cat, or a weight-loss plan so your cat can groom again.

Prevention

Keep your cat at a healthy weight so they can reach every part of their coat, and brush regularly, daily for long-haired cats. Use year-round parasite prevention recommended by your vet, and treat every pet in the home when fleas or mites are found.

Feed a complete and balanced cat food appropriate for age and health. Keep up yearly checkups, twice a year for seniors, so that thyroid and other problems are caught early. A change in the coat is one of the easiest early signs of illness for an owner to spot, so mention it at your next visit even if your cat seems fine otherwise.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.