Dog Dandruff: Causes, Treatment & Best Shampoos

By Sarah Bennett, Certified Animal Nutritionist

What Is Dog Dandruff?

Dandruff in dogs — medically known as seborrhea — is the excessive shedding of dead skin cells, usually visible as white or grey flakes on your dog's coat and bedding. Healthy skin continuously replaces itself, but when this process is disrupted, skin cells accumulate and flake off in clumps. Some dogs also develop seborrheic skin that is greasy and foul-smelling rather than dry, a condition called seborrhea oleosa. Understanding which type your dog has is the first step toward effective treatment.

Primary vs. Secondary Seborrhea

Seborrhea is categorised as either primary or secondary, and the distinction matters enormously for treatment.

Primary seborrhea is an inherited disorder of skin cell turnover. Breeds most commonly affected include Cocker Spaniels, West Highland White Terriers, Basset Hounds, and Labrador Retrievers. In these dogs, the skin-renewal cycle runs too fast from birth or early life, producing chronic dandruff that cannot be cured — only managed. Genetic testing and biopsy can confirm the diagnosis.

Secondary seborrhea is far more common and results from an underlying condition that disturbs normal skin function. Once the root cause is identified and treated, the dandruff typically resolves. Common triggers include:

• Allergies — environmental allergens (pollen, dust mites, mould) and food sensitivities both inflame the skin barrier, leading to flaking. Dogs with atopic dermatitis frequently show dandruff as a secondary symptom.
• Parasites — Cheyletiella mites, sometimes called "walking dandruff," are surface-dwelling mites that cause intense flaking along the back and can be transmitted to humans. Fleas and lice also irritate skin and disrupt its barrier function.
• Dry environment — low indoor humidity, especially during winter heating season, strips moisture from the skin just as it does in people.
• Poor diet — diets lacking adequate omega-3 fatty acids, zinc, or vitamin E impair the skin's ability to maintain a healthy barrier. Cheap kibbles heavy in fillers and low in quality fat are a frequent culprit.
• Hormonal imbalances — hypothyroidism and Cushing's disease both interfere with skin cell regulation and often present with dandruff alongside other systemic signs.
• Fungal or bacterial infections — Malassezia yeast overgrowth and bacterial pyoderma produce scaling and can be secondary to allergies or immune compromise.

How to Identify the Cause

Before reaching for a shampoo, take a close look at your dog's overall health. Ask yourself: Has the diet changed recently? Is there excessive scratching, hair loss, or redness? Is the flaking concentrated on the back (suggestive of Cheyletiella) or generalised? Are there other symptoms — weight gain, lethargy, increased thirst — that might point to a hormonal cause? Flaking that appears alongside these signs warrants a vet consultation rather than home management alone.

One simple test for Cheyletiella: place a white sheet of paper under your dog and watch for moving specks. The mites are just large enough to be visible to the naked eye, giving the impression that the dandruff itself is "walking."

Treatment: Medicated Shampoos

For most cases of dandruff, a good shampoo routine is the cornerstone of treatment. Different active ingredients target different problems:

• Selenium sulfide or zinc pyrithione — control yeast overgrowth and reduce cell turnover. Useful for greasy seborrhea and secondary fungal involvement.
• Salicylic acid and sulfur — soften and remove scale, making them ideal for dry, flaky seborrhea. These are often combined in veterinary shampoos.
• Chlorhexidine — an antiseptic that addresses bacterial component if present.
• Colloidal oatmeal and aloe vera — soothing and moisturising; excellent for maintenance between medicated baths or for mild environmentally-induced dandruff.

Always allow the shampoo to contact the skin for 5–10 minutes before rinsing. For primary seborrhea, weekly baths may be necessary long-term. For secondary seborrhea, frequency can often be reduced once the underlying cause is controlled.

Omega-3 Supplements for Skin Health

Dietary intervention is one of the most underused tools for managing canine dandruff. Omega-3 fatty acids — specifically EPA and DHA from fish oil — reduce skin inflammation, strengthen the epidermal barrier, and improve coat quality. A typical therapeutic dose is 20–55 mg of EPA+DHA per kilogram of body weight per day, but always consult your vet before supplementing, especially in dogs on blood thinners or with bleeding disorders.

Zinc is equally important. Deficiency is particularly common in Siberian Huskies and Alaskan Malamutes, who have higher zinc requirements than most breeds. Look for foods that list a quality meat source as the first ingredient and include omega-rich fats such as salmon" title="Can Dogs Eat salmon" title="Can Dogs Eat salmon" title="Can Dogs Eat salmon" title="Can Dogs Eat Salmon? Safety Guide + The Raw Fish Warning">Salmon? Safety Guide + The Raw Fish Warning">Salmon? Safety Guide + The Raw Fish Warning">Salmon? Safety Guide + The Raw Fish Warning">salmon oil or flaxseed.

Environmental Adjustments

If dry indoor air is contributing to your dog's flaking, a room humidifier set to 40–60% relative humidity can make a noticeable difference within a few weeks. During winter, this simple step often reduces dandruff without any change in shampoo or diet. Ensure your dog is also well-hydrated — many dogs drink less than they need, particularly on dry kibble diets.

When to See a Vet

Book an appointment if dandruff is accompanied by hair loss, skin redness, a foul odour, significant scratching, or any systemic symptoms. Your vet may recommend skin scrapings to rule out mites, fungal culture, allergy testing, or blood panels to check thyroid and adrenal function. Attempting to manage these conditions at home without a diagnosis risks missing a treatable underlying disease and allowing it to progress.