What Causes Excessive Shedding in Dogs - and Can Diet Help?

At a glance

• Excessive shedding is most commonly linked to poor nutrition, seasonal changes, allergies, or thyroid disorders
• Protein deficiency is the leading dietary cause — hair follicles need amino acids to grow and maintain healthy fur
• Omega-3 fatty acids reduce inflammation at the skin level, which directly lowers excess shedding
• Visible improvements in coat condition typically appear within 6 to 8 weeks of a dietary change
• Sudden, patchy, or year-round heavy shedding warrants a vet check to rule out medical causes

Why is my dog shedding so much?

Excessive shedding happens when the normal hair growth cycle is disrupted — by poor nutrition, hormonal imbalance, allergies, stress, or seasonal change. All dogs shed. The question is whether the amount is normal for the breed and time of year, or a sign that something else is going on.

Breed matters enormously. Double-coated breeds like Huskies, Golden Retrievers, and German Shepherds go through heavy seasonal moults twice a year, typically in spring and autumn. This is normal. Single-coated or low-shedding breeds like Poodles and Shih Tzus that suddenly shed heavily are more likely to have an underlying cause worth investigating.

The most common triggers for excessive shedding are: nutritional deficiency (especially protein, omega-3s, or zinc), environmental or food allergies, parasites such as fleas or mites, thyroid disorders, and chronic stress. Diet sits at the top of the list because it is the easiest to address — and it affects every other system in the body, including the skin and coat. Diet influences far more health conditions in dogs than most owners realise, and coat quality is one of the clearest outward signs of what a dog is eating.

Which nutrients directly affect coat health?

Three nutrients do most of the work when it comes to coat quality: protein, omega-3 fatty acids, and zinc.

Protein provides the amino acids that build keratin, the structural material in every strand of hair. A dog getting insufficient protein — or protein from poor-quality sources that cannot be properly absorbed — will have a dull, brittle coat that sheds more than usual. Around 90% of a dog's hair is keratin, so protein is non-negotiable.

Omega-3 fatty acids, particularly EPA and DHA, reduce inflammation in the skin. Inflamed skin means weakened hair follicles, which shed more easily. Fish-based meals are one of the most reliable dietary sources of EPA and DHA. Marleybones' Sassy Salmon meal is built around salmon as the primary ingredient, making it a straightforward choice for dogs where coat condition is a concern.

Zinc regulates the speed at which skin cells renew themselves. Too little zinc and the skin becomes dry and flaky, and hair follicles grow weaker over time. Zinc is found in meat, particularly red meat, and in seeds like hemp and chia, both of which feature in Marleybones' vet-developed recipes.

Can switching to a better diet actually reduce shedding?

Yes, and the change is measurable. Studies on canine skin and coat health consistently show that dogs fed nutritionally complete diets with adequate protein and omega-3 content have significantly less hair loss and healthier skin barrier function than those on low-quality diets. The effect is not instant — expect 6 to 8 weeks before visible improvements appear, because that is how long a full coat growth cycle takes.

The quality of the protein source matters as much as the quantity. Protein from whole meat is more bioavailable than protein from heavily rendered meat meals or plant-based fillers. Bioavailable means the dog's body can actually absorb and use it, rather than passing it through as waste. A food with 28% protein from whole chicken or salmon will deliver more usable amino acids to the skin and coat than one with 30% protein from low-grade derivatives.

Ultra-processed dry food — standard kibble — is made at temperatures that degrade heat-sensitive nutrients like omega-3s and some B vitamins. Fresh or gently cooked food retains more of these nutrients in their active forms. That is one reason owners switching from kibble to fresh food frequently report coat improvements within a couple of months. Every dog is different — build your personalised Marleybones feeding and health plan tailored to your dog's age, size, and health requirements.

When does shedding mean something more serious?

Diet does not explain every case of excessive shedding. Certain patterns point to medical causes that need proper investigation.

See a vet if your dog shows any of the following:

• Patchy hair loss or bald spots — this points to ringworm, mange, or hormonal disorders rather than diet
• Shedding accompanied by red, inflamed, or itchy skin — likely allergic skin disease, which needs diagnosis before treatment
• Sudden heavy shedding in a breed that does not normally moult heavily — thyroid disorders (hypothyroidism) are a common cause in middle-aged dogs
• Hair loss around the eyes, mouth, or paws specifically — this pattern is associated with zinc-responsive dermatosis, more common in Nordic breeds
• Shedding alongside weight gain, lethargy, or coat changes like dullness and coarseness together — this combination strongly suggests a hormonal issue

If shedding is persistent, worsening, or accompanied by any of the above signs, get a vet assessment before changing the diet. Nutritional improvements support a healthy coat, but they will not resolve an underlying medical condition. If allergies are involved, the approach to diet needs to be more targeted and ideally guided by a vet or veterinary nutritionist.

For dogs where no medical cause is found, improving diet quality is the single most effective step an owner can take. Focus on whole-meat protein sources, foods with naturally occurring omega-3s, and meals that are complete and balanced to FEDIAF standards, meaning they meet all established nutritional requirements rather than just some of them.

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FAQs

How long does it take for a diet change to reduce shedding?

Most dogs show visible coat improvements within 6 to 8 weeks of switching to a higher-quality diet. This aligns with the canine hair growth cycle. Skin cell turnover begins improving sooner, but the coat itself takes time to reflect the change.

What is the best food for a dog that sheds excessively?

A complete diet with high-quality animal protein as the primary ingredient and a reliable source of omega-3 fatty acids, such as salmon or linseed, gives the best results. Avoid foods where the protein source is vague (listed as