Why does my dog shed so much?

If you’re asking “Why does my dog shed so much?” you’re not alone. People come with this question for different reasons: someone with allergies wants to understand exposure; a person thinking about adopting compares breeds; another owner is worn out from daily lint-rolling and vacuuming; and sometimes a normally tidy coat suddenly changes and the owner worries about health. Clear answers help with everyday life (cleaning, allergy planning), with choosing the right dog for your household, and with knowing when to get veterinary help.

At a glance: why your dog is shedding so much

Most heavy shedding is normal and linked to breed and season: double-coated dogs and some working breeds are designed to moult heavily at predictable times. Beyond that, excess shedding may be related to skin disease, hormonal imbalances, external parasites, poor nutrition, stress, or age-related changes. I typically see routine seasonal moulting and periodic spikes tied to indoor heating or lighting; sudden, patchy, or severely increased shedding that comes with itching, sores, weight loss, or behavior change should prompt a veterinary visit right away.

Under the fur — how a dog’s coat is built and what triggers hair growth and loss

A dog’s coat exists to protect and to regulate temperature. Each hair follows a growth cycle with three main phases: a growth or anagen phase, a short transition or catagen phase, and a resting or telogen phase when the hair is more easily lost. The proportion of hairs in those phases varies by breed and by the signals the dog receives from its environment, so some dogs naturally shed more at baseline.

Coats are commonly described as single or double. Double-coated breeds have a dense undercoat and a longer guard coat; the undercoat traps air for insulation and is the layer that often comes out in large clumps during moulting. Single-coated breeds shed differently and often less visibly. Because the coat is part of the body’s thermal strategy, changes in temperature, day length, or household lighting can shift the timing and intensity of shedding.

Hormones and internal signals also influence hair growth and retention. Thyroid hormones, sex hormones, and stress-related hormones are likely linked to changes in hair thickness and timing of hair loss. Skin health—driven by nutrition, oil production, and microscopic organisms on the skin—affects how securely hairs are anchored. When those internal systems are out of balance, shedding patterns may change in ways that are more than just “seasonal.”

When shedding peaks: seasonal cycles, age effects and stress-related spikes

Seasonal moulting is the most familiar pattern: many dogs shed heavily in spring to lose the thicker winter undercoat and again in fall to prepare for cooler or warmer months, depending on the region. Those cycles are largely driven by photoperiod—the length of daylight—which tells the body to shift hair growth phases. Outdoors, this rhythm is predictable; indoors, it can be muddled because artificial lighting and thermostats confuse the dog’s cues.

Indoor climate plays a surprisingly large role. Central heating dries skin and may increase shedding; constant indoor temperatures and long artificial light exposure can blur seasonal signals so a dog seems to shed more steadily rather than in clear waves. Puppies will shed their baby coat as the adult coat comes in, and pregnant or nursing females commonly show heavier shedding after giving birth. Older dogs can also shed differently as skin thins and hormone levels change with age.

Stressful events—moving house, new family members or pets, boarding, and abrupt changes in routine—may trigger temporary increases in hair loss. Illness and systemic disease can do the same; when shedding follows a major life event or illness, it may be part of a broader pattern rather than a simple grooming issue.

Watch these red flags: signs that shedding points to a health problem

Not all hair loss is harmless. Patchy hair loss, obviously thinning areas, bald spots, scabs, or raw skin suggest an underlying problem and warrant veterinary attention. Intense itching, constant scratching, licking or chewing at a spot, visible fleas or mites, and signs of a secondary skin infection (pustules, odor, greasiness) are also warning signs. If heavy shedding comes on very suddenly or is paired with other changes—loss of appetite, weight loss, lethargy, increased thirst, changes in urination, or behavioral shifts—it may suggest a hormonal, metabolic, or systemic issue that needs prompt diagnosis.

If you’ve tried simple home care and the coat doesn’t improve, or if treatments for fleas or topical problems don’t help, that lack of response itself is a reason to see a veterinarian. I often advise clients that when grooming and basic skin-care measures fail to reduce shedding or when the dog is uncomfortable, it’s time for diagnostics rather than guessing.

Practical action plan for owners: immediate steps and follow-up care

1. Observe and document: Photograph problem areas and note timing, whether shedding is seasonal or sudden, and any other changes in appetite, stool, energy, or behavior. A short timeline helps your vet decide next steps.
2. Review diet and hydration: Check that the food meets AAFCO standards for your dog’s life stage; consider whether recent food changes could coincide with coat changes. I may recommend a diet high in omega-3 and omega-6 fatty acids or vet-approved supplements if a deficiency is suspected, but start by discussing diet with your vet before adding supplements.
3. Start a grooming routine suited to the coat: Brush with the right tool for your dog’s coat type (see below), bathe with a gentle, dog-specific shampoo when needed, and avoid over-bathing which can dry the skin. Keep records of what you try and how the coat responds.
4. Check for parasites and reactions: Use appropriate flea prevention and examine the skin for fleas, flea dirt, or mites. If you find parasites or severe irritation, treat or seek veterinary help promptly.
5. When abnormalities persist: Book a veterinary consultation. Expect the vet to perform a skin exam, possibly skin scrapings, cytology, fungal cultures or Wood’s lamp exam for ringworm, and basic bloodwork (including thyroid testing) if indicated. Referral to a board-certified veterinary dermatologist may be advised for chronic or complex cases.

Keeping your home and dog comfortable: grooming routines, cleanup and training tips

Designate a grooming area with an easy-to-clean surface and a place where the dog can feel secure. I find that dogs respond better when brushing is predictably short at first and paired with treats and calm praise; build session length gradually. Desensitize your dog by touching the coat, lifting paws, and using the brush briefly so the dog learns the routine without anxiety. For dogs that resist, break sessions into several short, positive experiences rather than one long stressful one.

Control the environmental burden of hair with practical zones: keep bedrooms or furniture covered with washable throws, establish “no-hair” zones for allergy sufferers, and place doormats at entrances to reduce tracked fur. A regular cleaning routine—vacuuming with a pet-rated unit, using lint rollers or sticky brushes on textiles, and washing bedding weekly—reduces visible shedding. Consider a HEPA air filter in rooms used frequently by the dog if airborne dander contributes to household allergies.

Adjust grooming seasonally: increase undercoat removal during peak moult and scale back in slower months. Coat conditioning—regular but not excessive bathing with a moisturizing, dog-specific conditioner—can reduce breakage and make loose hair easier to remove during brushing.

Tools, gadgets and safe products that actually help control shedding

Select tools that match your dog’s coat. Undercoat rakes and de-shedding blades can remove large amounts of loose undercoat from double-coated dogs when used gently; slicker brushes and combs work well for tangles and finer coats. Grooming gloves are a lower-stress option that many dogs tolerate; they remove loose hair while allowing close contact. Avoid overly sharp blades or aggressive tools that can abrade the skin.

Use pet-rated shampoos and conditioners formulated for dogs; human products can disrupt skin pH and lead to drying or irritation. If your dog has sensitive skin or dermatitis, choose products with mild, hypoallergenic formulations and consult your vet before trying medicated shampoos. For cleaning the home, a high-quality pet-rated vacuum (preferably with a HEPA filter) and washable slipcovers for furniture cut down on hair load. Lint rollers and rubber brooms are handy for quick spot cleaning between deeper cleans.

When considering supplements or topical products, check with your veterinarian first. Omega fatty acid supplements, for example, may help coat quality in some dogs but are not a substitute for diagnosing an underlying medical cause. If you use over-the-counter deshedding sprays or treatments, choose ones made specifically for dogs and follow instructions closely to avoid skin irritation.

References and further reading (veterinary sources)

• Merck Veterinary Manual: “Alopecia and Hair Loss in Dogs” — merckvetmanual.com
• American Veterinary Medical Association (AVMA): “Dermatologic Conditions in Dogs” guidance pages
• World Small Animal Veterinary Association (WSAVA): “Global Nutrition Guidelines for Dogs and Cats” and skin-health recommendations
• Veterinary Dermatology (journal): review articles on canine atopic dermatitis and practical management strategies
• American College of Veterinary Dermatology (ACVD): resources for finding a board-certified veterinary dermatologist and position statements on skin disease