What age do female cats go into heat

The phone calls often go like this: “We need to bring our kitten in right away. We are afraid she might be rabid!” Rabies is certainly not something to rule out lightly as it is a very serious disease. However, when further questioning shows that the cat involved is a 6-month-old female kitten who has not been spayed, I can be quite sure she is simply “in heat.” But I understand the confusion. The behavior changes of a cat in heat are enough to concern any family.

When To Expect Going Into Heat

Most female cats are at close to 80 percent of their adult size when they have their first estrus or “heat.” For shorthaired cats, that is generally around 6 months of age. Some kittens go into heat as early as 4 months, while longhaired cats may not have a first heat until about 18 months, though that is less common. Siamese cats are notorious for coming into heat at an early age.

The estrus cycle in a cat is stimulated by daylight length — with 12 hours of daylight generally being the activator. Cats are classified as “seasonally polyestrus.” This means that a cat will have multiple heat cycles during the breeding season. For cats in the Northern Hemisphere, March to October is generally considered to be prime breeding season. Figure your cat will cycle through every 14 to 21 days from March to September or October, unless she is bred or spayed.

Breaking Down The Heat Cycle

There are four stages to the feline heat cycle.

1. Proestrus: The first stage is proestrus. This is a short period of one to two days during which your cat may be restless or more affectionate. She may have changes to her “meow.”

2. Estrus: Next comes estrus or the real “heat” period. This is when your kitten could become pregnant. Ideally, cats should not be bred until they are at least a year of age to allow for full growth, but a pregnancy could occur this early on.

For the four to six days of full estrus or being in heat, your kitten will show some unusual behaviors, and some of these cause many families to panic. The meows become louder, more frequent to the point of being nonstop and very insistent. Think loud meows all day and night. While your kitten may suddenly become very affectionate, she may also grab at you with her claws out or bite if picked up. She will roll over while crying and may posture with her rear end raised while treading with her hind paws. Cats do not show the bloody discharge associated with dogs in heat, so the behavior changes may be the first tip off that your kitten has hit puberty.

3. Interestrus: Most cats then move on to interestrus. A few will have a prolonged estrus. If your kitten has not been bred, she will stay in this interestrus stage for seven to 14 days then revert back to proestrus. During interestrus, the bizarre behaviors will fade out.

Cats are induced ovulators. This means your cat will not spontaneously ovulate. The stimulus of being bred causes the ovulation. Breeding or even an attempted breeding that failed to cause pregnancy will send your kitten out of heat. If she is not pregnant, this false pregnancy will last about five weeks and then she will head back into heat. If she is pregnant, she will deliver kittens in about 63 days.

4. Anestrus: Your cat’s reproductive system goes into rest during the anestrus period. This is from about November through January when the daylight hours become shorter. During this time, your cat’s reproductive system becomes quiescent and her personality returns to the cat you love.

What Causes The Heat Cycle?

The hormone sequence for the whole estrus cycle starts off when the hypothalamus (part of the brain) signals the pituitary gland to releasefollicle stimulating hormone or FSH. The FSH travels to the ovaries and starts up follicle production. The follicles then produce estrogen, which triggers the “in heat” behaviors. When a cat is bred, the pituitary gland then sends out luteinizing hormone or LH, which causes the ovary to release the eggs from their follicles. This is ovulation. Each egg can potentially develop into a kitten once the sperm of a male cat fertilizes it.

The average number of eggs released is four, but cats have had as many as 18 kittens in one litter!

The egg empty follicles develop into corpus luteum cysts. Now they switch over to produce the hormone progesterone. Progesterone is the hormone that is essential to maintain the pregnancy. This is a rather complex set of hormonal stimuli and responses. Any misread signals along the way would lead to infertility.

Living With A Cat In Heat

Most families choose to spay their adolescent cat after going through just one heat. The nonstop noise and behavior changes can be overwhelming. If you choose to leave your female kitten intact, your veterinarian may be able to show you how to stimulate her vagina to cause ovulation. That will cut down on the number of heat cycles in each breeding season, but it won’t stop all of them. Cats who are left intact but not bred may have a higher risk of developing a pyometra or infected uterus. The risk of developing breast cancer is also increased.

The good news is that your kitten’s bizarre behavior is much more likely her coming into heat than having rabies!

By: Dr. Deb M. Eldredge

Feature image: Gina Cioli/I-5 Studio

June 21, 2021

The term ‘in heat’ means when a cat is ready to mate, which can be a daunting thought for any pet owner. If you’re wondering what to do when your cat is in heat, call Best Friends Vets on 01202 485880 to book an appointment with a nurse. Talk to our team about your cat’s cycle and discuss neutering.

Get advice from our nurses

Our vet Stefan recommends neutering your kitten at four to five months of age to prevent unwanted pregnancies (neutering after this age is recommended too). If your cat is allowed outside at this age without being neutered, there’s a good chance that he/she will mate, and kittens will be on their way. When it comes to cats in heat, here is everything you need to know.

How often cats are in heat and at what age

Female cats reach sexual maturity and can breed from about 4 months old. They will then come into heat (or season) every year around February to October. Female cats have many short periods roughly 2-3 weeks apart. They do not ovulate until they are mated, so this period of heat cycles can be lengthy. Older queens (female cats) can still have cycles, albeit fewer, until they are spayed. Longer days can trigger reproductive activity, leading to many kittens being born in March, April, and May.

A male cat’s critical heat season is usually September to March. However, a tom (male cat) that has reached full maturity (typically 6-12 months) can mate with a female cat whenever she allows it.

How to tell if your cat is in heat – symptoms & behaviour:

• The sound of a cat in heat is different from normal meowing. It’s extreme vocalising or yowling as if in pain. Male & female cats call out to each other, and this can sound very odd.
• Females are flirtatious and extra affectionate – back arching, rubbing & rolling on the floor.
• Male cats in heat are more attention seeking too but can be pushy and demanding.
• Raised hindquarters, moving the tail from side to side.
• Keen to be out of the house in search of a mate – cats in heat can roam further too.
• Male cats in heat will ramp up their urine spraying activity and get into more fights.
• It is uncommon for female cats in heat to bleed.

How to care for a female cat in heat

Your queen will be feeling out of sorts during her season. She can feel especially confused if it is her first one. You can help by trying to keep her happy and distracted. Entertain her with games, treat-filled toys, and activities in the house.

If you are considering having your cat neutered, the team at Best Friends Vets are here to help if you have any queries or concerns. Feel free to contact us.

Benefits of neutering

There are plenty of benefits to having your cat neutered. For female cats, their ovaries and uterus are removed. This will prevent pyometra – a serious uterine infection. Spaying also lowers the risk of mammary tumours and reduces the spread of infectious diseases from mother to kittens. In males, castration prevents testicular cancer and lowers the risk of prostate cancer.

Neutering also provides important population control with fewer unwanted kittens. Plus, it eliminates male cats on the doorstep fighting, spraying urine, and vocalising – which can only be a good thing.

Talk to us about cat neutering.

Chances are you’ve heard the phrase “like a cat in heat” before, but what does that mean? “In heat” refers to when a cat is fertile and ready to mate.

A cat’s first heat happens when she hits puberty at six to 10 months old. Her oestrus cycle will usually last four to five days and, unless she becomes pregnant, she will be in heat again in roughly two to three weeks.

If your cat has not been spayed (neutered/desexed), she will behave differently when she is in heat. Keep an eye out for these behaviours:

1. She is more vocal than normal

Also known as “calling,” your cat may wail, moan or meow more than usual while she is in heat. Her cries may sound distressed – and may even keep you up at night.

Consider this: If you have a naturally noisy cat, look for other signs to help you determine if she is in heat.

2. She’s restless

Her inability to relax or get comfortable could be a sign that she’s in heat – especially if this behaviour is coupled with calling.

3. A low crawl

Your cat may low crawl and moan at the same time if she is in heat. This is normal oestrus behaviour and not a sign that your cat is in pain.

4. Extra affection

She may rub up against furniture, doorways and especially your ankles to spread her scent – which has changed subtly during this cycle.

Consider this: If she’s not normally affectionate, this sign is a pretty good indicator.

5. Excessive grooming

During this time, your cat’s genital area will likely become swollen and uncomfortable, which means she might spend more time grooming this area.

6. Your indoor cat wants to be outside

If your cat is in heat, she may want to roam outdoors to spread her scent. She might also hope to meet a receptive male.

Consider this: If you have a cat flap, be sure to lock it so she can’t get out (and so other cats can’t get in).

7. Her tail tells a tale

Your cat may stick her buttocks in the air and move her tail to one side, which is the mating position.

A cat in heat will require some extra work and attention from you. Plus, there’s always the possibility of a female cat becoming pregnant and having kittens. If you don’t want to breed your cat, you should have her spayed by your vet to avoid this cycle and the risk of an unwanted or unexpected litter.