Why does my cat have dandruff?

It’s just dandruff. No big deal, right?

Maybe. Maybe not.

There is more than one reason why cats get flaky skin. Some of those reasons are not worrisome and can be managed by you at home. Some require swift veterinary care. Certain causes can be highly contagious to humans. Eeek!

Let’s get to the bottom of those flakes.

What is dandruff? How is it different from dander?

Let’s define dandruff first, so we’re all on the same page.

A cat’s skin is the largest organ in his body. It provides a barrier against the world, protecting him from parasites and infections, from the elements, and even from injury. It helps regulate his temperature and keeps his body from losing too much moisture.[1]

The skin is constantly renewing itself, growing new cells to replace existing ones, which eventually die. It is normal for the skin to shed the old dead cells to make room for the next generation.

The shedding of the dead cells is not something you’d notice, unless you have an allergy to cats. In fact, we all shed skin cells continuously, but the dead cells are so thin and transparent that we don’t really see them flake off.

The result of normal shedding of a cat’s skin cells is what we call “dander.” If you’re allergic to cats, you probably believe that you’re allergic to dander, but, in fact, you’re probably really allergic to a protein in cats’ saliva that ends up on skin cells when a cat licks herself to groom. (For more information on allergies to cats, read, “Is there such a thing as a hypoallergenic cat?”)

Dandruff, in contrast to dander, is very noticeable and involves visible white flakes. These white flakes are clumps of dead skin cells that haven’t shed normally. Certain disease processes can cause a cat’s skin to shed too many skin cells all at once, or to stick together rather than flutter off individually. Other health issues prevent a cat from grooming properly and helping rid herself of normally shed skin cells.

If your cat has dark fur, the problem may look worse than it really is. Conversely, if your cat has light fur, or extra-long fur, it could be hiding a more serious problem.

How do you know if dandruff is something to worry about?

Should you take your cat to the vet for dandruff?

Dandruff may be “just dandruff,” flaky skin due to dryness or some other relatively benign cause, that you can address with your vet at your next regularly scheduled appointment.

But dandruff can also be a sign of something far more serious, from chronic pain to metabolic disorders and cancer. Certain parasites and infections cause dandruff, too, and some of these can be spread to humans. In other words, sometimes dandruff isn’t a simple problem and requires a more immediate visit to the vet.

Even if the underlying cause of the dandruff isn’t serious, sometimes the symptoms themselves can be serious. A cat who is constantly licking an inflamed, irritated patch of skin can cause the skin to open, leading to an infection, for example.

If your cat is experiencing dandruff with any of the following additional symptoms, make an appointment with your veterinarian today:

• Itchiness
• Hair loss
• Vomiting
• A change in appetite
• A change in water consumption
• More frequent grooming, or obsessive grooming
• Skin redness
• A change in litter-box habits, or “accidents”
• Visible parasites, like fleas or lice
• Skin wounds or lesions. Human family members may develop lesions, too.[2]

Let’s discuss the potential causes of dandruff in more detail.

What causes dandruff in cats?

Skin that is too oily

It seems counterintuitive, but sometimes dandruff is caused by skin that is too oily.

The skin contains sebaceous glands that generate an oily substance called “sebum.” Sebum is made up of fatty acids that help keep the skin soft and the hair shiny. Sebum is also antimicrobial, meaning that it can help keep the skin safe from bacteria and other potential invaders.[3]

But sometimes there is too much of a good thing. Too much sebum can cause a skin disease called seborrhea or seborrheic dermatitis. It’s not clear whether a cat’s body produces more oils in response to something like yeast growing on the skin, or if yeast and bacteria just thrive on all that extra oil. Either way, seborrhea results in irritated, red, itchy skin that flakes.

While seborrhea can be a disease all by itself – and some cat breeds, like Persians or Himalayans, are just more prone to it – seborrhea can also be a sign that something else is going on in a cat’s body.[4] We will discuss some of those issues below.

Because there are so many potential causes of seborrhea, there is no simple “one-size-fits-all” treatment.

It will be up to your vet to try to get to the bottom of what’s causing your cat’s oily skin. Your vet may need to perform skin scrapings and hair pluckings to look for parasites, and skin cultures to look for infections. Your vet may check your cat’s blood for chemical or hormonal imbalances. Treatment options will depend upon the results of these tests, but can include anything from antibiotics to dietary supplements, corticosteroid treatments, or special shampoos.

Skin that is too dry

You’re not going to believe this, but skin that is too dry can also be called seborrhea. The dry kind is called “seborrhea sicca,” while the oily kind is called “seborrhea oleosa.”[6]

Oddly, the same diseases that can cause oily seborrhea can also cause the dry kind, and quite often a cat will suffer from both at the same time. It’s like what we humans call “combination skin.”

Dry and oily seborrhea are basically the same problem: there is something going wrong in the delicate balance between shedding old skin cells and growing new skin cells, and/or in the production of sebum.

While there are many potentially serious causes of both kinds of seborrhea, sometimes your vet can go down every rabbit hole and come up with nothing. This is called “idiopathic seborrhea.” In other words, “we don’t know what’s causing your cat’s seborrhea.”

This is more common than you think.

The good news, in this case, is that your cat isn’t suffering from something more serious. The bad news is there is no specific treatment for idiopathic seborrhea, although there are some shampoos, topical treatments, and dietary supplements that your vet may encourage you to try to treat your cat’s symptoms.

Fungal infections

Ringworm is a fungal infection of the skin. The spores of fungal organisms, called dermatophytes, enter a cats’ skin through a bite or a scratch mark and attack the outermost layer.

A cat suffering from ringworm may have circular or irregular patches of hair loss, brittle hair, and red patches of skin – and yes, dandruff. Ringworm is highly infectious and transmissible to humans.[7]

Malassezia dermatitis is an overgrowth of yeast on a cat’s skin. It’s normal for a cat to have a small number of these yeast organisms on their skin; dandruff happens when they grow too numerous. Note that Malassezia infections can be associated with more serious conditions in cats, including feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), diabetes, and other syndromes. You and your vet will need to get to the bottom of why your cat is experiencing a sudden Malassezia infection.[8]

Parasites

Fleas and lice bite, and the bites are itchy! Itchy cats scratch, and excessive scratching can cause skin inflammation, leading to dandruff.

Some cats are allergic to flea saliva and suffer from a condition called “flea bite allergy dermatitis.” This allergy to fleas can cause irritation and damage to skin, and dandruff as a result.[9]

Demodectic mange is an inflammatory skin disease in cats caused by tiny mites that are so small you cannot see them without a microscope. This condition is actually pretty rare in cats, but cats who suffer from it lose their hair around their eyelids, head, neck, flank. They suffer from itchy crusty skin patches, too.[10]

Cheyletiellosis is a disease caused by Cheyletiella mites. It’s sometimes called “walking dandruff” because you can see these larger mites crawling around on top of the skin. Horrifying! This is a very contagious parasite – humans are susceptible to it, too.[11] Luckily, walking dandruff can be prevented by the regular use of flea-control products.[12]

(Read all about keeping fleas under control in this post.)

Under-grooming due to obesity or arthritis

Cats who are overweight suffer in many ways, including losing the ability to groom themselves properly. The pain of arthritis, an inflammation of the joints, can cause a cat to under-groom, too.

Cats need to be able to bend and twist comfortably to be able reach all their “corners” with their tongues and claws. Extra weight on a cat provides a physical obstacle to grooming and arthritis just makes it too uncomfortable to do so. A cat needs the flexibility to be able to reach all the way back to the base of her tail, and underneath her own armpits.

Without proper grooming, a cat’s skin can become irritated and even infected. Obese cats often suffer from dandruff in the spots they can’t reach, especially the bases of their tails and their lower backs.

Excessive grooming

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Under-grooming can cause dandruff, but so can over-grooming. Cats can take self-care a little too far sometimes. I’ve written a whole blog post about this topic, which you can read here: “Excessive grooming in cats.”

Do you bathe your cat very frequently? If you bathe your cat frequently, using any product other than cat shampoo can irritate their skin. Cat skin is more acidic than human skin and needs a pH balanced shampoo. I recommend Earthbath or Burt's Bees because they are both designed to be used on cat skin.

Allergies

An allergy occurs when a cat’s immune system overreacts to something in her world. In addition to fleas, mentioned above, cats are most commonly allergic to things they eat and to things in their environment.

Environmental allergies include things like grass, pollen, mold, funguses, and dust. But your cat can also be allergic to manmade things such as cigarette smoke, perfume, and household chemicals, including cleaning products. Cats can also experience allergies to certain foods.[13]

When a cat is suffering from allergies, his body will often react by developing skin sores, hair loss, and you guessed it: dandruff.

Serious diseases

Sometimes a cat’s skin is the “canary in the coal mine” for something more serious that is going on in her body.

Many whole-body diseases also affect the skin. Skin inflammation is often seen in diseases that affect a cat’s organs, including the liver, kidney, and pancreas. Diabetes, too, can cause skin changes, including redness, crusting, oozing, and lesions.

Hypothyroidism, where a cat’s body doesn’t make enough thyroid hormone, while rare in cats, can cause hair loss and dry, scaly skin.

Too much adrenal gland hormone, called hyperadrenocorticism, can cause skin changes including hair loss and seborrhea.[14]

Certain cancers, such as cutaneous lymphoma, a kind of skin cancer, can have symptoms that include itching and scaly skin.[15]

While I would not rush to a dire conclusion the first time you find a few flakes in your cat’s fur, it is a reason to be alert to other symptoms or changes, and to bring your cat to the vet if you are concerned.

Aging

As a cat ages, her skin loses elasticity and becomes drier due to reduced activity in the sebaceous glands. Sometimes, as a cat gets older, blood flow to the skin declines and that can contribute to dandruff, too.

Aging and arthritis often go hand-in-hand, and reduced grooming combined with drier skin can be an unfortunate combination for skin health.

Anxiety

Stress and anxiety can be a root cause of dandruff, typically because the fear and emotional discomfort that cats feel can lead to over-grooming or under-grooming, which, in turn, lead to skin changes and dandruff.[16]

What makes a cat feel anxious may not be something that we humans understand. What a cat views as a threat might seem unreasonable to us. But any change in their world can be emotionally upsetting to them, from something as simple as moving the furniture in a room, to something as dramatic as a death in the family.

The “good” news, if you could call it that, is that dandruff is unlikely to be the only sign your cat will display if anxiety is causing dandruff. Your cat may show signs of destructiveness, may have accidents outside the litter box, or may show some signs of aggression. Here are a few posts that might be helpful if you think your cat might be suffering from anxiety:

Separation anxiety in cats

Why is my cat peeing on my bed?

Why does my cat bite me gently?

Diet

Dandruff might be a sign that your cat’s diet is lacking in the nutrients that are essential to the healthy functioning of his skin. The process of growing new skin cells uses up to 30% of the protein your cat consumes, so any food you feed should include high-quality, digestible proteins that are easily absorbed.

A cat’s food also needs to include essential fatty acids like Omega-3s and Omega-6s. Fatty acids cannot be synthesized by a cat’s own body so you need to make sure they are included in what you are feeding.[17] Note that some well-intended low-fat cat diets might not include enough fatty acids for the health of your cat’s skin.

Vitamins also contribute to skin health, especially Vitamin A, which regulates cell growth and the production of oils.[18] Just be sure you are feeding a high-quality diet intended for cats.

Environment

Do you live in a dry climate or a humid, warm climate? Do you keep the heat on high in the winter?

Ironically, both humidity and dryness cause the same problem: overproduction of sebum by the skin’s sebaceous glands. The overproduction of skin oils can lead to dandruff (see above).

Note that cats in general have a tendency toward dehydration. They don’t have a strong thirst drive and they’re notoriously fussy about drinking from their water bowls. A dry environment can exacerbate a cat’s propensity to become dehydrated.

What can I do about my cat’s dandruff?

If only there were a simple fix.

Sometimes there is, depending upon the cause of your cat’s dandruff:

What not to do when your cat has dandruff

When you look at flaky cat skin, you might be tempted to directly apply moisture in the form of oils or lotions to provide relief.

Don’t.

Most of these products get trapped in the coat, causing a greasy mess. Moreover, a cat is likely to ingest a large amount of the product while grooming.[20]

If your cat is suffering from the greasy form of seborrhea, you may be tempted to bathe your cat more frequently to keep her fur shiny and clean.

A single bath may help relieve oily skin, but too much bathing can cause a change in the skin’s pH, creating more problems than it solves.[21] Overbathing, or bathing with the wrong shampoos can actually encourage the skin to produce more sebum. Read this post, “How to bathe your cat,” and reach out to your veterinarian for guidance.

Read this related post

What to do about matted cat fur

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Dawn LaFontaine is a lifelong animal lover who always seems to have a little pet hair in her keyboard. Her blog, Kitty Contemplations, helps cat guardians better understand and care for the special beings they share their lives and homes with. Her cat-products business, Cat in the Box, sells beautiful, well-made, and award-winning products that she designed to meet the biological needs of cats.

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FOOTNOTES

[1] “Structure and Functions of the Skin.” HSE, www.hse.gov.uk/skin/professional/causes/structure.htm.

[2] “Don't Brush off Feline Dandruff.” CVMBS News, 8 July 2021, vetmed.tamu.edu/news/pet-talk/dont-brush-off-feline-dandruff/.

[3] Moriello, Karen A. “Structure of the Skin in Cats - Cat Owners.” Merck Veterinary Manual, Merck Veterinary Manual, Aug. 2018, www.merckvetmanual.com/cat-owners/skin-disorders-of-cats/structure-of-the-skin-in-cats.

[4] Hunter, Tammy, and Ernest Ward. “Seborrhea in Cats.” vca_corporate, vcahospitals.com/know-your-pet/seborrhea-in-cats.

[6] “Cat's with Oily or Flaky Skin.” DOUXO® S3, Douxo, 31 Aug. 2021, www.douxo.com/us/cat-skin/cat-dandruff-and-dry-flaky-skin.

[7] “Understanding Cat Dandruff-Royal Canin ® - Royal Canin.” Understanding Cat Dandruff-ROYAL CANIN ® - Royal Canin, www.royalcanin.com/us/cats/health-and-wellbeing/cat-dandruff-and-dry-skin.

[8]  “Fungal Infection (Malassezia Pachydermatis) of the Skin in Cats.” PetMD, https://www.petmd.com/cat/conditions/skin/c_ct_malassezia_dermatitis.

[9] “Dandruff in Cats: Causes and Treatment.” FirstVet, firstvet.com/us/articles/4-common-causes-of-dandruff-in-cats.

[10] “Mange in Cats.” Crystal River Animal Hospital, Veterinarian in Crystal River, Dog Vet, Cats, Horses, Mobile Equine Veterinarian, crystalriveranimalhospital.com/mange-in-cats.php.

[11] Anderson, Maureen. “Cheyletiella - the WALKING DANDRUFF.” Worms & Germs Blog, 19 May 2015, www.wormsandgermsblog.com/2008/12/articles/diseases/parasites/cheyletiella-the-walking-dandruff/.

[12] “Don't Brush off Feline Dandruff.” CVMBS News, 8 July 2021, vetmed.tamu.edu/news/pet-talk/dont-brush-off-feline-dandruff/.

[13] Flowers, Amy. “Cat Allergies: Learn about the Symptoms, Causes, and Treatments.” WebMD, WebMD, 23 Feb. 2021, pets.webmd.com/cats/cat-allergy-symptoms-triggers#1. 

[14] White, Stephen D. “Whole-Body Disorders That Affect the Skin in Cats - Cat Owners.” Merck Veterinary Manual, Merck Veterinary Manual, www.merckvetmanual.com/cat-owners/skin-disorders-of-cats/whole-body-disorders-that-affect-the-skin-in-cats.

[15] Downing, Robin. “Cutaneous Lymphoma in Cats.” vca_corporate, vcahospitals.com/know-your-pet/lymphoma-in-the-cat.

[16] “Cat Anxiety.” Battersea Dogs & Cats Home, 16 Feb. 2021, www.battersea.org.uk/pet-advice/cat-advice/cat-anxiety.

[17] “Understanding Cat Dandruff-Royal Canin ® - Royal Canin”

[18] ibid

[19] “How Do You Get Rid of Cat Dandruff? What Causes Dandruff in Cats?” Purina, www.purina.com/articles/cat/health/cat-dandruff.

[20] Biggs, Caroline. “How to Recognize and Treat Cat Dandruff.” Martha Stewart, 6 May 2020, www.marthastewart.com/7797387/cat-dandruff-treatment-tips.

[21] “5 Tips for How to Get Rid of Cat Dandruff and Dog Dandruff.” PetMD, PetMD, 27 Sept. 2021, www.petmd.com/dog/grooming/evr_multi_dandruff_free_pet.