When Do Cats Go Into Heat?

While many people choose to spay their cats to help decrease the chances of a pregnancy and extra kittens running around the house, if your cat isn't spayed, she will eventually go into heat. If you have an adopted cat and you're not sure how old she is, you may not know if she's already had her first heat or when to expect the next one. While a cat's heat cycle can be a little confusing, once you learn to tell when your cat is going into heat, you can better anticipate when the next one will come.

When Do Cats Go Into Heat?

Most cats will have their first heat by the time they are 6 months old.  But certain environmental factors can cause it to happen more quickly.  Certain breeds, like Siamese, may go into heat as early as 4 months, while for other breeds the typical age for going into heat is 10 months. 

If you're not sure how old your cat is and are trying to determine if they may be close to or have already had their first heat, their teeth can give you some clues. If they still have their milk teeth or have recently lost them, they are likely still a while from their first heat. However, a full set of adult teeth or any plaque build up on the teeth — a sign of a cat that is a few years old — indicates an adult cat that is likely already having heat cycles.

What Are the Signs That a Cat Is in Heat?

When cats go into heat, they tend to display some specific behaviours. These include:

• Changing vocalizations from a normal meow sound to more of a howling noise
• Being more affectionate
• Rubbing up against objects more than normal
• Excessive and loud purring
• Holding the tail straight up
• Raising the rear
• A small amount of vaginal discharge, which will appear bloody
• Spraying urine to attract mates
• Trying to get outside more

How Often Do Cats Go Into Heat?

After the first heat, you can expect your cat to go into heat for a week approximately every two to three weeks. As long as your cat doesn't get pregnant or you don't spay her, she will continue this cycle. Unlike humans, cats don't age out of being able to reproduce, which means they are technically able to get pregnant and have kittens throughout their entire lives.

If your cat does get pregnant during a heat, the gestation period lasts around 65 days, during which your cat won't go into heat. However, cats can go into heat and be able to get pregnant just 1 to 4 weeks after delivering a litter.

How to Help a Cat in Heat

While the heat cycle is a natural and normal part of an unspayed cat's life, there are some things you can do to help make your cat more comfortable during this time.

• Provide plenty of affection. Your cat may want to spend more time with you or be closer to you than normal.
• Give her a hideout. On the other hand, some cats prefer to not be bothered during this time. If your cat seems to be hiding more than usual, giving her a specific place to get away from everything can help.
• Increase the amount of exercise. During a heat, your cat may have more energy, and you can help channel this by providing leashed walks or extra play sessions.

If you don't have experience with a cat in heat, it can be challenging to tell if your cat is in heat or is having another behavioural or medical issue. If you're not sure why your cat has a sudden change in behaviour, it's always a good idea to take her into the vet for a checkup.