The Feline Heat Cycles
Unlike dogs, female cats do not cycle at regular intervals throughout the year. Cats tend to come into heat in relation to the season of the year. The mating season in cats is determined by a number of factors, among them the length of daylight, and the presence of other cats. When there are 12 hours of daylight and other conditions are optimal, the hormonal system is activated, and the queen begins the reproductive cycle. The natural mating season of cats in the Northern Hemisphere is from March to September. Although the majority of cats cycle in the spring and fall, some cats may come into heat at any time of the year.
Throughout the breeding season, queens go into and out of heat several times but do not always at regular intervals. They may exhibit continuous heat cycles in early spring (averaging 14 to 21 days from the beginning on one cycle to the beginning of the next), followed in late spring by cycles that are farther apart. Each queen establishes her own normal rhythm.
Most female cats reach puberty and have their first heat cycle between five and nine months of age, occasionally earlier. Yet we do not want her to becoming pregnant until the queen is physically – and mentally ready. Persians as a breed is considered late matures and may not reach puberty until one and a half years of age.
The estrous heat cycle or reproductive cycle of cats has four distinct stages: Anestrous, proestrus, estrus and metestrus.
Anestrous is the term used where the queen does not come into heat and her ovaries are in a quiescent (inactive) stage. This would be the period of no sexual activity. In most areas of the United States this would run from late September through mid-January. The low light and short length of daylight is a primary factor in reducing the heat cycles during the winter months. Cats kept indoors may be stimulated to cycle from artificial light sources artificially lengthening the queen’s day. These light levels are similar to those experienced during the peak breeding seasons of early spring and fall they start cycling.
Proestrus is the term used to describe the stage of estrous immediately following anestrus. In this stage of heat the ovaries are becoming active in follicle formation and lasts from one to four days. You may notice that the vulva enlarges slightly and appears somewhat moist from the hormonal changes, this is usually apparent. The queen shows increased appetite and restlessness, utters short low calls and displays more than usual affection for her owner. This is best described as the period where the cat is coming into heat, but is not yet ready to be bred. Hormones such as the follicle stimulating hormone (FSH) and estrogen help promote the egg development occurring during this phase.
Estrus is the period of the heat cycle where the cat is able to become pregnant. It is what breeders refer to as heat, or the call. Length is variable but usually lasts 10 to 14 days. During this period the owner may notice behavioral and other physical changes in the female. Hormones greatly influence the cat’s behavior at this point. The cat “in heat” will vocalize and urinate frequently. She will appear overly passionate by rolling, rubbing and assuming the breeding posture with the head and forelegs low to the ground and the rump area held high. As the urge to mate becomes pronounced, her cries become alarming --- sounding like those of an animal in pain. This is the call, which attracts toms from near and far. Unlike the female dog, the queen usually has little if any noticeable vaginal discharge in either the proestrus or estrus phase.
The actual breeding or copulation takes place during the estrus phase. Copulation usually lasts 10 seconds or less, but although the time is short, most females will breed repeatedly over a 24 to 48 hour period helping to assure semen from the male is present when the queen’s eggs are ovulated. Queens are “induced ovulators” and the act of breeding stimulates the female to release or ovulate her eggs. In other mammals (dog’s, cattle and humans) ovulation occurs even if breeding does not. A cat not bred, and therefore not induced to ovulate, will usually go out of heat within 10 to 14 days. Because the cat was not induced to ovulate by breeding, she will come into heat every two to three weeks (or sooner) until breeding and ovulation occurs.
It is possible to artificially induce ovulation in the cat with vaginal stimulation. A clean rectal thermometer can be lightly inserted in to the vagina to induce ovulation and therefore “knock” the queen out of heat. This will slow the cycle but she will come back into heat again.
The time immediately after estrus is termed the metestrus period. The female will not pay attention or accept the male at this time and will return to her normal self.
The materials, information and answers provided through this website are not intended to replace the medical advice or services of a qualified veterinarian or other pet health care professional. Consult your own veterinarian for answers to specific medical questions, including diagnosis, treatment, therapy or medical attention.
Return to Articles