Course 15 · Double Coats · Lesson 2 of 12

What is the yearly cycle of a double coat?

Published 29 October 2026 · Updated 29 October 2026 · About 6 minutes · General information only. This lesson does not diagnose or treat any condition.

The yearly cycle of a double coat moves through winter density, spring blowing, summer lightness, autumn blowing, and winter regrowth, driven by daylight, temperature, hormones, and indoor living. The cycle is not rigid: indoor dogs may blow more evenly through the year, outdoor dogs may have sharper seasonal peaks, and individual dogs vary by age, health, and breed. Understanding the cycle helps owners plan grooming frequency, bathing, and home cleaning, and helps them recognise when a change is not part of the normal cycle.

How does the cycle work through the seasons?

In winter, undercoat is dense and full, providing insulation, and guard hairs lie over it, protecting it from weather. Shedding is usually lower, although indoor heating can cause steady shedding. In spring, as daylight increases and temperatures rise, winter undercoat is released in a heavy blow, over two to four weeks, sometimes longer. Loose undercoat comes out in clumps, the coat looks patchy, and grooming needs increase sharply. In summer, the coat is lighter, with less undercoat, and guard hairs provide protection from sun and heat, provided the coat is clean and ventilated. Shedding may continue at a lower level, and the coat needs regular combing to remove loose hair and to keep air flowing to skin. In autumn, summer coat is shed and winter undercoat grows in, in a second blow, often less dramatic than spring but still noticeable. In late autumn and winter, undercoat thickens again, and the cycle repeats. Hormones, neutering, age, and health can shift the timing and intensity, and a dog that has been ill, has had surgery, or has changed diet may have an irregular cycle that should be discussed with a vet if it persists.

How do indoor living, light and heating affect the cycle?

Indoor living blurs the seasonal cycle, because artificial light and central heating reduce the signals that trigger blowing. Indoor dogs may shed steadily all year, with smaller, less distinct blows, or may blow almost continuously. Outdoor dogs, exposed to natural daylight and temperature change, tend to have sharper, more predictable blows. That difference matters for planning: an indoor dog needs a steadier grooming routine all year, while an outdoor dog needs intensive grooming during blows and less intensive grooming between them. Owners should learn their dog’s pattern over a full year, noting when blowing starts, how long it lasts, and how much hair is released, rather than assuming a textbook spring and autumn pattern. A move, a change in heating, or a change in daylight exposure, such as moving from outdoors to indoors, can shift the cycle, and grooming should adjust accordingly. The cycle is a guide, not a calendar, and the dog’s coat, felt by hand each week, is the best indicator of where it is in the cycle.

How should grooming adjust through the cycle?

Grooming should adjust in frequency, not in force or method. During blowing, deshed every two to three days in sections, with skin checks, as in the shedding course. Between blows, comb weekly to skin, check friction areas, and remove loose hair before it packs. Bathing should be timed to dirt and coat condition, not to the cycle alone, and should always be followed by full drying and combing. In summer, focus on ventilation: a clean, deshedded coat allows air to reach skin, and the dog needs shade, water, and rest in heat, as in lesson 8. In winter, focus on drying and matting: wet undercoat that stays damp can mat and chill the dog, so drying after rain, snow, or baths is essential, as in lesson 9. Tools should stay the same through the cycle: comb, rake, gentle slicker, and sparing deshedding tool, with no blades or clipping. The routine should be reviewed at each phase change, with notes on what worked, so next year’s cycle can be planned.

What changes are not part of the normal cycle?

Changes that are not part of the normal cycle include sudden heavy shedding outside blowing periods, patchy hair loss, bald patches that do not regrow, coat thinning over months, dull or greasy coat with a new smell, and skin change such as redness, flaking, sores, or itching. Behaviour change, appetite change, weight change, or lethargy accompanying coat change also point away from a normal cycle. Hormonal changes, illness, medication, and stress can affect the coat, and those effects should be discussed with a vet, especially if they persist. Owners should not assume that a coat change is seasonal without checking pattern, skin, and behaviour, and should not try to correct a cycle change with diet, supplements, or products without veterinary advice. A normal cycle is predictable, even, and accompanied by healthy skin and a comfortable dog. Anything outside that pattern, especially a sudden or patchy change, deserves a vet conversation, with notes on timing and pattern.

When should you stop and get help?

Contact a vet if the coat cycle is irregular, if hair loss is patchy or sudden, if skin changes, if the coat does not regrow, or if the dog seems unwell. Contact a groomer for help planning grooming through blowing, for a professional deshed, or for advice on tools and frequency for that coat. Do not clip, shave, or use blades to manage a cycle change, and do not increase bathing or brushing forcefully. The yearly cycle is a rhythm to work with, through gentle, frequent grooming in blowing phases and steady combing between them, and recognising when the rhythm breaks is part of good coat care.

Winter density, spring blow, summer lightness, autumn blow and winter regrowth form a yearly rhythm, and grooming that follows that rhythm, with more frequent deshedding in blowing phases, keeps a double coat healthy all year.

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