A cat's coat is not one thing shedding on a schedule; it is thousands of follicles each running a 3-phase cycle on its own clock. Anagen lasts 30-60 days, catagen 1-3 days, telogen 60-90 days, and the whole coat links loosely into 2 big sheds a year. Once you know which phase a patch is in, brushing frequency, hairball risk and the meaning of a bald spot stop being guesswork.
Three phases, one follicle
Anagen is growth: the follicle pushes a new hair out from the bulb, with blood supply and pigment cells switched on. Catagen is the 1-3 day shutdown, when the bulb detaches from the blood supply and the hair becomes a dead shaft sitting in a shrinking follicle. Telogen is the 60-90 day rest, during which that dead hair stays anchored and is displaced only when the next anagen hair grows underneath it. Shedding is not a phase; it is the collision between a new anagen hair and an old telogen one.
That single fact explains most coat complaints. A hair shed in telogen is being pushed out, not falling out, so no shampoo changes the timing. The timing belongs to the follicle's exit from telogen, and that exit is hormonal.
Why the phases take 30-60 and 60-90 days
Follicle length sets the clock. Short hairs on the face and paws finish anagen in 30 days or less; long guard hairs on the back and tail can run 60 days or more, which is why a shaved patch on the flank grows back on a different schedule from one on the muzzle. A cat clipped for surgery in November may show a visible 4-6 cm difference in coat length through February.
Nutrition gates the same clock. Growing hair is mostly protein, and a diet below 26% protein on a dry-matter basis, or one short on the sulfur amino acids, produces a duller coat and slower regrowth in 6-10 weeks.
Two sheds a year, driven by day length
The trigger is photoperiod, not temperature. Melatonin from the pineal gland tracks night length, and as days lengthen past roughly 12 hours the spring shed starts; when they fall back under 12 hours the autumn shed follows. Northern-hemisphere timing lands around March to May and September to November, with the autumn shed usually the heavier of the 2 because it lays down a denser undercoat.
Indoor life muddies this. A room lit to 200-300 lux for 14-16 hours a day in winter reads as permanent summer, and cats in that environment often shed a low, steady trickle all year instead of 2 clean events. Air conditioning that holds a flat 20-22 C removes the secondary temperature cue as well. Neither harms the cat, but it makes the calendar table below less reliable.
What a year looks like at 40 degrees north
| Month | Daylight | Coat phase | Brushing |
|---|---|---|---|
| January | 9.4 h | Dense winter coat, most hairs in telogen | 1-2 times a week |
| March | 12.0 h | Spring shed begins, undercoat releases | 3-4 times a week |
| May | 14.3 h | Peak spring shed, new anagen hairs pushing out | 4-5 times a week |
| July | 15.0 h | Thin summer coat, light shedding | 1-2 times a week |
| September | 12.4 h | Autumn shed starts, heaviest of the 2 | 4 times a week |
| November | 9.7 h | Winter coat set, telogen hairs still anchored | 2 times a week |
Read it as a default, then adjust to what the brush collects. A 10-minute session that fills a palm-sized wad of undercoat is a coat that is shedding; the same session producing a few strands is not, whatever the month says.
Brushing: how often, how long, which tool
Two sessions a week of 5-10 minutes keeps most short-haired coats ahead of the shed. At peak shedding, go to 10-15 minutes 4-5 times a week, and work in the direction of the coat, not against it on the belly and armpits. Tool choice matters more than effort: a metal undercoat rake with 5-8 mm teeth reaches the undercoat on a dense coat, a slicker brush handles the topcoat on a kitten or a senior, and a fine-toothed flea comb is for the face and the base of the tail.
Signs you are overdoing it: pink skin, a coat that parts to the skin in lines, or a cat that leaves after 2 minutes. Under-brushing shows up differently, as matting behind the ears and at the armpits, which forms in 5-10 days on an older cat that has stopped self-grooming effectively.
Hairballs, mats and the 10-year shift
Passing 1-2 hairballs a month in spring is ordinary; 2 or more a week, or any hairball with lethargy and no appetite, is a reason to call a vet. Mats are a different failure: they form where the coat is fine and the cat cannot reach, and on a long-haired cat they tighten within 7-10 days.
From about 10 years the coat thins on the belly and dulls overall, partly because grooming time drops and partly because muscle loss makes the spine and hips harder to reach. Hyperthyroidism, common in cats over 10, produces the opposite at first — a greasy, unkempt coat with increased shedding — and it is worth a thyroid panel when the coat changes without a seasonal reason.
When shedding is a symptom
Symmetrical thinning over the flanks and the back of the thighs, bald patches over 2 cm across, hair loss that continues 4 weeks past a shed, or any patch with redness, scale or scabbing are not coat-cycle events. Nor is a coat that suddenly stops growing back after clipping. Each of those needs a vet visit with a skin scrape and, in an older cat, blood work; none of them is fixed by a better brush.
Five steps for the next shed
- Write the 2 shed windows on a calendar and start brushing 2 weeks before each one, not after the sofa is covered.
- Brush 10 minutes, 4-5 times a week for 3 weeks in peak season, then drop back to 2 sessions of 5 minutes.
- Keep the room at 20-22 C and stop lighting it past 12 hours in winter if you want 2 clean sheds instead of a year-round trickle.
- Check protein on the label: 26% dry-matter minimum for an adult cat, more for a kitten or a nursing queen.
- Look at the skin every session — pink, scaly or scabbed skin at 2 sessions in a row means a vet call, not more brushing.
Kittens run a different program: the fuzzy coat they start with turns into the adult one over roughly 4-6 months, alongside a weight curve that matters more than the fur, laid out in the growth chart guide. Winter static and mats are a humidity problem as much as a brushing one, covered in the winter coat notes, and coat condition is one of the better outward markers of age once you convert the cat's age.
Terms mentioned in this article
Frequently asked
How long does cat hair take to grow back?
Plan on 60-90 days for a visible result. A clipped patch re-enters anagen within 1-3 weeks, grows for 30-60 days, then rests for 60-90 more before the next hair pushes through. A shaved flank typically looks even again at 8-12 weeks, slower in a cat over 10.
Why is my cat shedding in winter?
Indoor light. A room held at 200-300 lux for 14-16 hours a day tells the pineal gland that nights are short, so follicles never get the long-night signal that triggers the autumn shed. Cutting artificial light to 12 hours and keeping the room at 20-22 C restores a cleaner twice-yearly pattern.
How often should I brush a short-haired cat?
Two 5-10 minute sessions a week is the baseline. In the 3-week peak of a shed go to 10-15 minutes 4-5 times a week with a 5-8 mm undercoat rake, then drop back. Stop if the skin turns pink or the coat parts to bare skin.