White flakes on a dark coat, scale on the bedding, or skin that feels rough or greasy under the fur: dandruff is common in dogs, and it is easy to brush off as “just dry skin.” Sometimes it is minor. Often, though, flaking is a sign of something underneath that your vet can find and treat.
Vets call excess flaking scaling, and when it comes with a skin-renewal problem they call it seborrhea. This guide explains the main causes and what to expect at the vet.
What dog dandruff actually is
Skin is always shedding its outer layer and building a new one. When something goes wrong in that cycle, or in the oil glands of the skin, the result is visible scale. Veterinary dermatologists group these problems as keratinization disorders, and excess scaling is the one sign they all share. [1]
So flaky skin in dogs can be dry (loose white or grey flakes, often with a dull coat) or greasy (yellow to brown, waxy scale that sticks to the hair and often smells), and sometimes both. [1][2]
Primary or secondary: why the cause matters
Seborrhea comes in two kinds: [1]
- Primary seborrhea is a defect in the skin itself, with no other disease behind it. It is uncommon. Breeds reported at higher risk include American Cocker Spaniels, English Springer Spaniels, West Highland White Terriers, Basset Hounds, Dachshunds, Irish Setters, Doberman Pinschers, German Shepherds, Shar-Peis and Labrador Retrievers, and signs usually appear before 2 years of age. [2]
- Secondary seborrhea is scaling caused by another condition, such as an allergy, mites or an underactive thyroid. [1]
Most scaling dogs have the secondary kind, and primary seborrhea can only be diagnosed after the other possible causes have been ruled out. [1][2] That is why vets look for the cause first rather than just treating the flakes. When the underlying disease is found and controlled, the flaking usually clears up or comes under good control; primary seborrhea, by contrast, generally needs lifelong care. [1]
Common causes of flaky skin in dogs
Allergies
Allergic skin disease is one of the conditions that most often leads to secondary scaling, and allergic dogs usually itch as well. [1][2] See why is my dog so itchy? and, if the flaking comes and goes with the seasons, seasonal allergies in dogs.
Hormonal disorders, including low thyroid
Hypothyroidism (an underactive thyroid) is usually seen in middle-aged and older dogs. [3] Typical skin changes are hair loss on both sides of the body that does not itch, darker skin, and a thin or bare tail, and secondary seborrhea and skin infection are common. [3] Many of these dogs also gain weight, slow down and feel the cold, so they may seek out warm spots. [3] Your vet confirms it with blood tests, not by the coat alone. [3]
Walking dandruff (Cheyletiella mites)
Sometimes the “dandruff” moves. Cheyletiella mites live on the surface of the skin and move quickly through the scale, which is where the name “walking dandruff” comes from. [4] The most common sign is dry, white scale, especially along the back. Itching can be mild or severe, and some animals carry the mites without showing signs. [4]
These mites are highly contagious and pass between dogs, cats, rabbits and people, where they cause itchy red bumps. [4] Treatment is prescribed by your vet, and every animal in the home is treated together, along with the home environment. [4] The mites and their eggs can be hard to find, so a vet may treat on suspicion even when tests come back negative. [4]
Skin infections
Scaly skin changes the skin’s surface and weakens its barrier, which makes it easy for bacteria and yeast to overgrow. These infections are a common complication of seborrhea, especially the greasy kind, and they add to the redness, itch and odor. [1][2] See pyoderma in dogs.
Scaly patches with hair loss can also be ringworm, a fungal infection that can spread to people. See ringworm in dogs and cats.
Zinc-related skin disease (uncommon)
Zinc-responsive dermatosis is a rare cause of crusts and stuck-on scale, together with redness and hair loss, mostly around the eyes, muzzle, chin and ears. [5] One form is seen mainly in Siberian Huskies and Alaskan Malamutes on normal diets; another affects fast-growing puppies on diets that are low in zinc or that block its absorption. [5] Do not add zinc or other supplements on your own; the diagnosis and any change to the diet need your vet.
What your vet will check
The key step is a careful search for an underlying cause. [2] Your vet will look at where the scale is, whether the coat is dry or greasy, any hair loss, odor and itch, and ask about your dog’s age, breed, diet, the season and other pets or people in the home who are itchy. [2][4]
Tests may include: [2][3][4]
- Skin samples under the microscope to look for bacteria and yeast
- Skin scrapings and tape samples for mites
- Tests for ringworm
- Blood tests, for example to check thyroid function
- Skin biopsy
Treating infections first sometimes reveals the real underlying problem, so keep any recheck appointments your vet asks for.
How flaky skin is treated
Treatment has two parts: fixing the underlying cause, and keeping your dog comfortable while that happens. [1][2]
Medicated shampoos and rinses. Bathing is a core part of managing scaly skin. Moisturizing shampoos and rinses suit mild dry scale, while heavier or greasy scale needs stronger scale-loosening and degreasing products. A moisturizing rinse is often used after the bath. [2] Your vet chooses the products and how often to bathe based on how scaly or oily the coat is. [2]
Do not use your own shampoo. Ask your vet before putting any shampoo made for people on your dog.
Treating infections and parasites. Bacterial and yeast infections need to be found and treated, because they make scaling worse. [2] Mites need a vet-prescribed treatment for every pet in the home, plus treatment of the home environment. [4]
When to see your vet
Make an appointment if:
- The flakes are new, heavy, greasy, or have a smell
- Your dog is itchy, or you see red skin, pimples, crusts or hair loss
- The flakes seem to move, or anyone in the home gets an itchy rash
- Your dog is middle-aged or older and the coat has become dry, thin or slow to regrow, especially if your dog also seeks out warm places
- Your dog drinks or urinates more than usual
- A puppy has scaly, crusty skin, especially around the face
FAQ
Is a little dandruff normal in dogs?
A few flakes now and then can be minor. But most scaling in dogs is a sign of another skin or body problem, so persistent or heavy flaking is worth a vet check. [1]
What is walking dandruff?
It is an infestation with Cheyletiella mites, which move through the scale on the skin’s surface. It is highly contagious and can spread to people. [4]
Can thyroid problems cause dandruff in dogs?
Yes. Dogs with an underactive thyroid often develop secondary seborrhea, along with hair loss that does not itch. [3] Your vet can test for it with blood work.
Will a medicated shampoo fix my dog’s dandruff?
It helps control the flakes, but lasting improvement depends on finding and treating the cause. [1][2]
Can I use dandruff shampoo made for people on my dog?
Not without your vet’s approval. Your vet can recommend a product made for dogs that suits your dog’s skin.
The bottom line
Dog dandruff is often a sign rather than a problem in itself. Allergies, hormonal disease such as low thyroid, mites, and skin infections are the usual culprits, and inherited seborrhea is diagnosed only after those are ruled out. Your vet can find the cause and recommend the right shampoo and treatment, so the flakes do not keep coming back.
This article is for general information and is not a substitute for veterinary advice. If your dog’s skin is flaky, itchy or changing, please see your veterinarian.
Sources
- Torres SMF. 3.1 Disorders of Keratinization: Learning Objectives, General Consideration and Classification. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology2/chapter/disorders-of-keratinization-canine/
- Torres SMF. 3.7 Canine and Feline Primary Seborrhea. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology2/chapter/idiopathic-keratinization-disorders-primary-seborrhea-dogs-and-cats/
- Torres SMF. 1.5 Hypothyroidism: Canine. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology2/chapter/hypothyroidism-canine/
- Torres SMF. 3.7 Cheyletiellosis: Small Animals. Small and Large Animal Dermatology Handbook, Vol. 1. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology/chapter/cheyletiellosis-small-animals/
- Torres SMF. 3.13 Canine Zinc Responsive Dermatosis. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology2/chapter/nutritional-related-keratinization-disorders-zinc-responsive-dermatosis-dogs/