Estrous Cycles in Cats

When does a female cat have her first estrous cycle?

Female cats have their first estrous (reproductive) cycle when they reach puberty (sexual maturity). On average, puberty occurs in cats at about six months of age, but this can vary slightly by the time of year (length of daylight hours).

The estrous cycle is better known as a cat’s heat cycle. Each cycle consists of several stages; the stage called estrus refers to when the female is sexually receptive, or in heat.

How often does a female cat come into heat?

Cats are seasonally polyestrous, which means they have multiple cycles during the breeding season. The breeding season will vary according to geography and environmental factors such as temperature and daylight hours. In the Northern Hemisphere, cats usually cycle from January until late fall. Cats in more tropical regions or mainly indoors may cycle year-round because of the increased number of daylight hours. Cats are sometimes referred to as “long day breeders” because of the link between longer daylight hours and going into heat.

What are the signs of estrus?

The most notable signs of estrus in cats are behavioral. Most cats become very affectionate, even demanding: they persistently rub against their owners or objects, such as furniture, constantly wanting attention. They roll on the floor more often. When stroked along the back or spine, they raise their rear quarters into the air and tread with their back legs. They also become very vocal. These behavior changes can become annoying to owners, and sometimes owners think their cat has an illness.

"The most notable signs of estrus in cats are behavioral."

Some female cats urinate more frequently or may even spray urine on vertical objects (marking) when they are in heat. The urine contains pheromones and hormones, both of which signal her reproductive state to other cats, and can attract tomcats (intact male cats). Tomcats may spray urine on the house to mark the territory (and female cat) as theirs; they may even attempt to enter the house to mate with the female.

How long does estrus last?

Each heat (the time during which the cat is receptive to males) generally lasts several days, with the average length being seven days; it can range from 1 to 21 days. If the queen (an intact female cat) is not mated during estrus, she will go out of heat for a short period of time — usually about seven days, but it can range from 2 to 19 days. Therefore, the complete estrous cycle of a cat can range from one to six weeks, with the average cycle length being about three weeks.

At what stage of the estrous cycle is the cat able to get pregnant?

A female cat can get pregnant at any time while she is in heat. Cats are induced ovulators, which means that the act of breeding stimulates the release of eggs from the ovaries. Most female cats require three to four matings within a 24-hour period for ovulation to occur. It only takes a minute or two for cats to mate, and they may mate multiple times in a short period. Females may mate with several different tomcats during this time, so it is possible that a litter of kittens may have several different fathers. Once ovulation has occurred, the female will go out of heat within a day or two.

How long does pregnancy last in a cat?

Pregnancy in cats lasts approximately 64 to 71 days, with an average of 65 days (nine weeks).

How can I prevent my cat from becoming pregnant?

The best way to prevent your cat from becoming pregnant is to have her surgically sterilized (spayed) by ovariohysterectomy or ovariectomy before she has her first estrous cycle. It can be difficult to predict when this first cycle will occur, so most veterinarians recommend performing the procedure when the cat reaches six months of age.

Should I let my cat have an estrus cycle or a litter of kittens before spaying her?

There are no valid reasons for letting a cat have an estrous cycle or have a litter of kittens before being spayed. Cats can become pregnant on their very first estrous cycle, increasing the chance of accidental breeding. Cats are indiscriminate, so a brother may breed with his sister, a father may breed with his daughter, and a son may breed with his mother.

A common myth is that female cats become more friendly and sociable if they are allowed to have a litter of kittens. This belief is not true and only contributes further to the serious problem of the overpopulation of cats.