Cat in Heat: Signs, How Long It Lasts and What to Do

A cat in heat (in estrus) is a female who is ready to mate, and she will usually tell the whole house: loud, repeated yowling, rolling on the floor, rubbing against everything, and crouching with her hindquarters raised and her tail to one side. A single heat lasts about 6 days on average, but anywhere from 2 to 19 days, and if she does not mate she can come back into heat roughly a week later, cycle after cycle, through the breeding season (Little, The Cat). For a pet cat who is not part of a planned breeding program, spaying is the standard answer: the Cornell Feline Health Center advises spaying before the first heat, and feline veterinarians support spaying cats not intended for breeding by 5 months of age.

This guide covers the signs, how long heat lasts and how often it returns, how young a kitten can come into heat, why a queen can come back into heat while still nursing kittens, and how to keep her safe and calm until she is spayed. If you are a breeder planning a litter instead, the free Creatures cat gestation calculator turns a mating date into a due date, no account needed, and the section on keeping a heat and breeding record explains how to log each cycle on her profile.

Signs of a cat in heat

Most of what owners notice is behavior. The Merck Veterinary Manual’s owner guide describes mating behavior as rolling, rubbing against objects, kneading with the back feet and loud, repeated yowling. The feline reproduction chapter in The Cat (Little, 2012) adds that queens in heat often call to attract males, may roll or thrash about on the floor, and stand with the tail turned to one side (Little, The Cat). The common signs, together:

• Calling. A loud, insistent yowl, often at night, that can sound like a cat in pain. It is aimed at any tomcat within earshot.
• Rolling and rubbing. Rolling on the floor, rubbing her cheeks, head and body against furniture, doorframes and your legs. Rubbing alone is everyday cat behavior; in heat it becomes constant and comes with the calling.
• The mating posture (lordosis). Chest and front legs low, hindquarters raised, tail held to one side, often treading or kneading with her back feet. Merck lists lordosis, with calling, as the signs breeders watch for.
• Restlessness and attention-seeking. Unusually affectionate one minute, restless the next, and trying to slip out of doors and windows.

New owners often mistake a first heat for illness, especially the yowling and the low crouch. If you are not sure whether your cat is in heat or in pain, call your veterinarian. Signs that point away from heat and toward a problem include vomiting, straining in the litter box, a discharge from the vulva, a swollen or painful belly, hiding and lethargy, or a cat who stops eating for more than a day or two. Those need a vet, not waiting it out.

How long is a cat in heat?

The heat itself averages about 6 days. The reproduction chapter in The Cat, written for veterinarians, gives an average of 5.8 days with a range of 2 to 19 days, so a heat that runs a week or more is still within normal (Little, The Cat).

If she does not mate and does not ovulate, the quiet stretch before the next heat (interestrus) averages about 7 days, again with a range of 2 to 19 days, according to the same chapter. That is why owners of an unspayed indoor cat describe her as “always in heat”: a 6-day heat, a week off and another heat can repeat through the whole breeding season.

Two things change that rhythm:

• Mating, or ovulation without pregnancy. Queens were traditionally described as induced ovulators, releasing eggs in response to mating, and the Merck Veterinary Manual still describes them that way. Little’s chapter notes that some queens ovulate on their own, without mating, so it is more accurate to think of cats as both induced and spontaneous ovulators. If she ovulates and is not pregnant, she has a false pregnancy (pseudopregnancy) that lasts about 40 to 50 days before she cycles again.
• Pregnancy. A cat who conceives stops cycling. Our guide to how long cats are pregnant covers the roughly nine weeks that follow.

How often do cats go into heat, and when does it start?

Cats are seasonal breeders that respond to day length. The Merck Veterinary Manual describes queens as “long-day, seasonally polyestrous” breeders, which means repeated heats while the days are long. The Cat explains the practical side: breeding catteries provide 12 to 14 hours of light a day to keep queens cycling, longhaired breeds seem more sensitive to day length than shorthairs, and many shorthaired queens, such as Siamese and related breeds, cycle year round regardless of daylight. An indoor cat living under electric lights may never have a clear off-season.

The first heat. The Cat puts the first heat typically between 5 and 9 months of age, at about 80 percent of adult body weight (roughly 5 to 7 pounds). Shorthaired breeds tend to reach puberty earlier than longhaired breeds, and season and body condition matter too. Do not wait for that window, though. The American Association of Feline Practitioners warns owners that a cat can be reproductively active, without necessarily showing obvious signs, as early as 4 to 5 months. A kitten who goes outdoors or lives with an intact male can be pregnant before anyone has noticed a heat.

Can a cat go into heat while nursing kittens?

Yes, and this catches a lot of owners out. Many queens do stop cycling while they nurse, a lactational anestrus that The Cat says can last up to 8 weeks after weaning, and most return to heat about 4 weeks after weaning if it is still the breeding season. But the same chapter states plainly that it is “entirely possible for a queen to return to estrus while still nursing.”

A 2023 study of 195 births reported by cat breeders found that 96 queens, 49 percent, came into heat during lactation, on average about 40 days after giving birth, with a range of 2 to 86 days, and four queens as early as the first week (Furthner, 2023). Small litters of one or two kittens, and births from February to April, were linked to an early return. Breeders linked over a third of those heats to problems such as less milk, diarrhea and a mother losing interest in her kittens.

Can she get pregnant then? The study’s authors describe a heat during nursing as possibly shorter and less fertile, but none of the sources we checked rules pregnancy out. Treat a nursing queen as able to conceive: keep her away from intact toms from the day the kittens are born. If she is not going to be bred again, International Cat Care advises having the mother spayed as soon as the kittens are weaned; ask your veterinarian about the timing for her.

What to do when your cat is in heat

If she is a pet: plan the spay

Spaying ends heat cycles for good, and it does more than stop the noise. The Cornell Feline Health Center advises that a female be spayed before her first heat, notes that spaying a kitten at three to six months will virtually eliminate her risk of mammary cancer later in life, and says it rules out pyometra, a potentially fatal collection of pus in the uterus. The AAFP’s position statement supports spaying cats not intended for breeding by 5 months of age. Pregnancy can be completely prevented by spaying, as Merck’s owner guide puts it.

If your cat is already in heat, call your veterinarian and book the spay; they will decide whether to operate now or after the heat ends. Hormonal drugs that delay or suppress heat exist; whether one is ever appropriate is a veterinarian’s decision, not something to try at home. Do not give your cat any human or leftover medication to calm her.

Until then: keep her in and keep her comfortable

• Keep her indoors and away from intact males. Check window screens, door habits and cat flaps. A cat in heat is determined, and toms will come to her.
• Keep the house calm. Extra play sessions and her usual routine help some cats settle. Expect the calling to continue anyway; it is not something she can switch off.
• Do not breed her to stop the heat. Pregnancy is not a cure for heat behavior, and a litter is a commitment to homes for every kitten.
• Write down the dates. Note when each heat starts and ends. If anything changes, or she seems unwell rather than restless, that history helps your vet.

Warning signs that need a vet

Heat is normal; illness is not. Call your veterinarian promptly if your unspayed cat has any discharge from the vulva, a swollen belly, or seems unwell (off her food, vomiting, hiding or lethargic), especially in the weeks after a heat. Cornell describes pyometra as potentially fatal, and it is far easier to deal with early. Also call if she seems to be in heat constantly with no quiet weeks at all, or if a spayed cat starts showing heat behavior, since both need an examination.

If you are breeding: timing a mating

Breeding a cat is a decision for someone with a plan for every kitten, registry rules for a pedigreed cat, and health testing of both parents. If that is you, the timing is straightforward:

• When to mate. Merck’s guide to breeding management of queens advises taking the queen to the tom when she shows signs of heat (calling, the mating posture), as early as the second day.
• How many matings. Because ovulation is triggered by mating, Merck advises multiple breedings over 2 to 3 days, with breaks between to prevent exhaustion and fighting. Queens normally roll and groom after each mating.
• Is she pregnant? If she conceives, she stops cycling. But a queen who ovulated without conceiving also stops for the 40 to 50 days of a false pregnancy, so a missed heat is not proof. Merck says your veterinarian can detect pregnancy by palpation or ultrasound 21 to 30 days after breeding.

Once you know the mating dates, the cat gestation calculator adds 65 days and shows a 63 to 67 day planning window. For an exposure window, such as a queen who was with the tom for three days, enter the first and last day and the window widens to match. Our guides to how many kittens a cat can have and the kitten growth chart cover what comes after the birth, and the kitten vaccination schedule covers the first vet visits. For a pedigreed litter, the free cat pedigree chart maker builds each kitten’s family tree, and our guide to cat pedigree papers explains CFA and TICA registration. Breeders of curly-coated cats can find breed specifics in our Selkirk Rex guide.

Keeping a heat and breeding record on Creatures

Veterinary references on breeding queens recommend keeping a written record for each one: her age at first heat, the date and length of each heat, her behavior, the dates and number of matings, whether each mating led to pregnancy or a return to heat, and the details of each pregnancy and litter (Little, The Cat). That record is just as useful for a pet you are about to spay, because it tells your vet exactly how often she cycles. Creatures is a free place to keep it on her profile. The calculator works for anyone; saving records needs a free account.

1. Add her. Create a profile for your cat with her name, birth date and photo.
2. Log each heat. On her Records tab, choose Records menu, then Log breeding / service. The form opens as a tracked mating, so turn Track as breeding cycle off, since she was not mated; otherwise Creatures would give her a due date and pregnancy reminders. Then enter the start date and, in Notes, what you saw (calling, rolling, the mating posture). The walkthrough is in adding a record.
3. Set a reminder. A heat record does not predict the next heat by itself. Add a Reminder for about a week after the heat ends if you want to watch for the next one, or a reminder to call the vet about her spay. See reminders and upcoming care.
4. Record a mating. If she is bred, open her Records tab, choose Records menu, then Log breeding / service, keep Track as breeding cycle on, and name the tom from his profile or type his name. Use a date range for several days together. Creatures shows her due date and window on her Breeding tab and schedules a pregnancy check and a due-date reminder. See recording a breeding.
5. If she comes back into heat. End the breeding and choose She came back into heat. Creatures keeps the mating in her history and clears the reminders for it, then offers to record her new breeding. See when a breeding doesn’t take.
6. Watch every queen at once. The Breeding dashboard lists each tracked pregnancy, soonest due first, with Expecting, Due soon and Overdue counts.
7. Log the spay. When she is spayed, add it as a Surgery record so her profile shows she no longer cycles.

Cat in heat FAQ

How long is a cat in heat?

About 6 days on average, with a normal range of 2 to 19 days. If she does not mate, the next heat often starts about a week later.

How do I know if my cat is in heat?

Loud calling, rolling on the floor, rubbing against furniture and people, and crouching with her back end raised and her tail to one side are the classic signs. If she seems ill rather than restless, call your vet.

How old is a cat when she first goes into heat?

Usually between 5 and 9 months, but the AAFP warns a cat can be reproductively active as early as 4 to 5 months. That is why spaying by 5 months is recommended for pet cats.

Do cats bleed when they are in heat?

Heat in cats is recognized by behavior, and the veterinary sources above do not list bleeding as a sign of a normal heat. Any blood or other discharge from the vulva is a reason to call your veterinarian.

Can a cat get pregnant while nursing?

She can come back into heat while nursing; in one breeder survey about half of queens did, some within the first week. That heat may be less fertile, but it is not safe to assume she cannot conceive. Keep her away from intact males.

Can a cat be spayed while in heat?

Ask your veterinarian. Some prefer to wait until the heat is over, others will operate; it is their call for your cat.

Does a male cat go into heat?

No. Male cats do not have heat cycles, but an intact male is drawn to a female in heat, which is why a queen in heat must be kept away from toms. The AAFP recommendation to sterilize cats not intended for breeding by 5 months of age covers males too.

Do this next on Creatures

Whether you are booking a spay for a first-time yowler or planning your cattery’s next litter, these are the useful next steps. Guides for every cat breed are on the Creatures cat page.