Do cats have a period?

Cats are polyestrus animals. An unspayed female cat would periodically go into the heat cycle in their fertile years. A cat’s heat cycle is composed of 4 stages. Proestrus, estrus, metestrus and anestrus are the stages that describe the cat’s varying degrees of receptiveness to a male cat’s attention. Dealing with a pet cat that is in heat can be challenging. Unlike dogs, cats would not show physical signs of being in heat. Dogs have vaginal swelling and bloody vaginal discharge. This condition that is not unlike the menstruation in humans is not present in felines. Cats manifest other signs of being in heat but these furry friends do not have a period.

There is not much difference on how the reproductive system of humans and felines work. Human’s menstrual cycle begins at puberty. Menstrual cycle in human females would start between 10 and 16 years of age. Mature eggs will be periodically released until the woman reaches the menopausal age that commonly happens between the ages 40 and 60. In humans and in other mammal species, menstruation involves the shedding of the uterine lining (endomitrium). Menstrual fluid or menstrual flow that contains cervical mucus, blood and vaginal secretions as well as the endometrial tissues will be shed. The shedding of this reddish brown fluid is called menstruation. Menstruation is commonly called “period”.

After attaining sexual maturity, female cats would periodically go into heat. The first heat cycle of a female cat occurs between 6 to 12 months although some breeds are known to go into heat as early as 4 months. Cats are noted to be seasonal breeders as most felines would manifest the signs of being in heat during spring and fall. While in heat, a female cat would be receptive to the sexual attention of toms. A queen will allow to be mated by several male cats so that the litter can be sired by different male cats.

A cat in heat may be prevented from being mated. This is a common situation in indoor-only cats. Cat owners that would not want the pet to get pregnant would make sure that the pet is kept away from male cats. There are also instances when the mating would not result to pregnancy. Humans and other mammals would have periods. The endometrial lining that was thickened in preparation for possible pregnancy have to be shed. The uterus has to be “cleaned” in preparation for the next ovulation period. The shedding of the uterine lining commonly termed “period” is not manifested by cats. Unlike other mammals, cats would not have bloody vaginal discharge.

Cats are induced ovulators. Eggs that ready in the ovaries will only be released if the cat is mated or manually stimulated. After being mated, a female cat would yowl and screech as if it is being murdered. The vocalization is due to the withdrawal of the barbed penis of the male cat. The barbed penis stimulates the queen to ovulate. Most mated queens will get pregnant. If pregnancy did not occur, the queen would go through the heat cycle again but unlike other mammals, cat would not have bloody vaginal discharge because cats are “covert menstruaters”. Instead of shedding the thickened uterine lining, blood and cervical mucus, these contents of the womb are reabsorbed. Cats have very efficient reproductive system. Cats have little wombs. It is expected that the amount of materials inside the womb would also be small and therefore can be easily absorbed. This is a highly efficient process as the cat would not lose vital substances. The menstrual blood will be reabsorbed by the uterine lining and retained in the cat’s body…a condition that is most beneficial especially in stray cats where maintenance of good health is rather difficult.