Cat in Heat (Estrus)

What is a cat in heat?

A cat in heat (also known as estrus or calling) is where an entire female cat is fertile and receptive to mating. It usually seasonal but can depend on several factors including the number of daylight hours, age and general health of the cat.

There are four phases of the cat’s heat cycle:

  • Proestrus
  • Estrus
  • Metestrus
  • Diestrus

This article looks at the second phase, estrus.

At what age does estrus begin?

Estrus begins at puberty when this starts varies from cat to cat and breed. Some oriental breeds (Siamese, Oriental shorthair) can call as early as four or five months. Other breeds may not reach
sexual maturity until 10 months.

Cat mating season

Most cats are seasonal maters, although some do go into heat and produce a litter at any time of the year. Typically the feline mating season begins in spring when the days start to become longer and runs through until autumn. Cats are polyestrous, which means they will have more than one heat cycle in a year.

Signs of estrus in cats

  • Affection: The cat may become extra affectionate towards people and other cats, rubbing against
    their legs, or weaving in and out between their legs or rolling on the floor.
  • Posture: If she is stroked, she may assume a mating position and lay her front half low, and raise her hindquarters, treading up and down with her hind feet, and move her tail from side to side. This is known as lordosis.
  • Persistent vocalisation: This is often louder than usual and can be described as a yowl. You may feel that cats in heat meow all the time!
  • Licking of the genital region: Beyond normal grooming, the vulva is often swollen with a clear discharge. If the discharge is cloudy or has a foul odour, see your veterinarian as the cat may have pyometra (an infection of the uterus).
  • Spraying: The female cat’s urine contains pheromones to attract male cats and she may spray on vertical surfaces such as walls and doors.

Some cats are silent callers and may display none of the above signs.

If your cat is in heat, keep her indoors. If she is an indoor cat already, be extra careful to keep windows and doors closed because she will be keen to get to a male cat and mate. Keep her away from intact male cats.

How long is a cat in heat?

Estrus typically lasts between 4-5 days. If your cat doesn’t become pregnant, then it will repeat every 14 to 21 days until she does become pregnant or the season’s change.

There are three possible outcomes:

  1. Pregnancy occurs.
  2. The cat mates but does not become pregnant, has a pseudopregnancy (false
    pregnancy) and comes back into heat 30 or so days later.
  3. The cat doesn’t mate or become pregnant and comes into heat 14 to 21 days later.

Frequency of estrus

If the cat doesn’t become pregnant during a period of heat, she will go out of season for 2 –3 weeks and then come back into heat. This can continue until the days shorten in autumn (around September in the Northern Hemisphere and March in the Southern Hemisphere).


The only guaranteed way to prevent a queen from coming into heat is to have her desexed (spayed). This also prevents unwanted kittens and provides several health benefits to the cat.

Entire cats are at risk of developing cancer of the uterus or ovaries, pyometra, and breast cancer.

Frequently asked questions about estrus in cats

Do siblings mate?

Yes, brothers and sisters will mate, fathers and daughters, mothers and sons. Cats do not discriminate when it comes to mating.

Is it painful for a cat to be in heat?

A cat in heat who is crying can sound like she is in pain, but it is not considered to be painful.

How do you stop a cat in heat from meowing all the time?

There is not much we can do to stop a cat in heat from calling. Once the cycle has finished, spaying the cat will stop her from coming into heat again. Meanwhile, a Feliway diffuser that contains synthetic pheromones may be of help in relaxing the cat while in heat. Learn more with our article: How to Stop a Cat in Heat from Meowing ALL The Time!

Is it possible for a litter of kittens to have different fathers?

Yes, cats are induced ovulators, their eggs are released after they have mated and can survive for up to 24 hours. If your cat mates with multiple male cats, then the kittens born can potentially have different fathers.

What should I do if my cat comes into heat?

Keep her indoors and away from any entire (Tom) male cats and book an appointment with
your veterinarian as soon as possible.

If she does get out and mate, it is not too late. She can still be desexed. Speak to your veterinarian about this. He may also wish to test for FIV and FeLV if she has mated with an unknown/untested tom.

Should I let my cat mate when she is in season?

Unless you are a registered breeder, and this is a planned mating then no, you should not allow your cat to mate for several reasons.

  • There is a huge cat overpopulation problem and breeding your cat just contributes to this.
  • For every kitten you have, which you may pass on to friends or neighbours, that is one
    kitten in a shelter who could have been rehomed.
  • Unless you have tested the tom (male cat), there is no way you will know if he has
    either feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV).
  • Desexing (also known as spaying) can be performed while your cat is in heat, but
    veterinarians typically prefer to spay a cat who isn’t in estrus.

My female cat has been spayed, but she is still coming into heat:

This sometimes happens in spayed cats if there are any remnants of the ovaries left behind during her spaying operation. This tiny portion of the ovary continues to produce hormones that trigger the estrus cycle in the cat, however, she cannot become pregnant.

Pregnancy signs:

The first sign of pregnancy is pinking-up, where the nipples become pinker and slightly swollen, which occurs around the third week of pregnancy.

Weight gain occurs around the fourth week of pregnancy.

Do female cats have periods?

Female cats do not shed their uterine lining, and there is no period.

How long is a cat pregnant?

A cat is pregnant for approximately 63 days.

How many kittens are in a litter?

This depends. First-time mothers may have a small litter of one or two. The average number of kittens in a litter is approximately 4 – 6.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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