Heat period in cats: Everything you need to know about the reproductive cycle.

Author: Dr. Buteață Andra – Pet Stuff Veterinary Hospital

The heat period in cats refers to that stage in the female’s sexual cycle, also known as estrus, during which she is receptive to mating and exhibits a specific behavior. A heat cycle is the normal reproductive cycle that occurs in unsterilized females. The cat’s breeding season occurs from early spring to late autumn.

Read on to understand the stages of the cat’s sexual cycle, how they manifest during the mating period, what to expect, and how to prevent these situations.

Sexual Cycle (Estrous Cycle, Gametogenesis)

With the onset of sexual maturity and until the physiological cessation of sexual function, the genital apparatus functions rhythmically and cyclically. The sexual cycle refers to the chain of phenomena and processes that occur and repeat, resulting in the release of one or more eggs ready for fertilization.

The duration of each sexual cycle and its phases depends on species, breed, climate, diet, and the individual.

In terms of the frequency of sexual cycles, females are divided into:

  1. Monoestrous (monocyclic): have one heat cycle per year (wild animals);
  2. Diestrous (dicyclic): have two heat cycles per year (dogs);
  3. Polyestrous (polycyclic): have multiple heat cycles per year (mare, cow, buffalo, sheep, sow, cat). In this group, the mare, sheep, and cat are seasonal polyestrous, while the cow and sow are continuous polyestrous.

In the evolution of a sexual cycle, two main functional stages are recognized: the follicular stage and the luteal stage. The follicular stage corresponds to estrogenic activity of the ovary, namely ovarian follicles, while the luteal stage is dominated by the action of progesterone secreted by the corpus luteum. The two main stages are separated by ovulation (which can be spontaneous or induced). Between the follicular and luteal stages, there is an intermediate stage characterized by the involution of the corpus luteum and sexual rest, known as diestrus in continuously polyestrous females and anestrus in seasonally diestrus females (physiological anestrus: before puberty, seasonal, postpartum, after the physiological cessation of sexual function; pathological anestrus: due to uterine conditions).

Within each stage, the following phases are distinguished:

  1. Follicular Stage: includes the proestrus and estrus phases;
  2. Luteal Stage: includes the metestrus and anestrus phases (hormonal rebalancing phase).

Ethological Changes (Behavioral)

In proestrus, the female shows increased interest in the male but does not accept mating. During estrus (heat period), the female expresses a desire for mating and accepts it. During the luteal stage, animal behavior is calm (quiet phase).

The cat is a seasonal polyestrous female, manifesting heat predominantly in the spring season. However, there are behavior changes in cats raised indoors. With a constant temperature and artificial light, they may experience sexual cycles throughout the year. This can be inconvenient for owners, leading them to consult a veterinarian with the desire to sterilize the cat quickly, but this is not recommended.

Source: personal arhive

The cat’s sexual cycle is incomplete because, in this species, ovulation is induced (occurs during mating with a male, which is why cats can mate with multiple males, giving birth to kittens with different physiognomic characteristics).

How Long Does a Heat Cycle Last?

Proestrus and estrus together last 9-14 days, with an average of 7 days. The cat begins to meow characteristically, even excessively, becomes very affectionate, rolls, rubs against objects, urinates more frequently and in more places (their urine contains pheromones that attract males from long distances), and adopts the lordotic position (raised hindquarters, raised tail), indicating receptivity to the male.

If mating occurs, ovulation will take place approximately 24 hours later. If the cat does not become pregnant, a pseudopregnancy period of 40-42 days follows. If mating does not occur during the heat period, mature follicles will age, quickly replaced by a new generation. Therefore, in the absence of a male, an unsterilized cat will be in a nearly constant state of heat.

After giving birth, heat may occur shortly, even while the female is nursing.

Source: personal arhive

At What Age Can a Cat Become Pregnant?

On average, a cat could enter heat between 6-9 months, but there are cases where heat cycles occur between 4 and 12 months. Short haired breeds might start heat earlier, while long-haired or larger breeds might not show signs of heat until 18 months.

For a successfully carried-out gestation in a developed organism, with controlled mating, it is recommended for the female to reach sexual maturity, and mating to occur after the age of 12-18 months.

How to Prevent a Cat from Going into Heat?

The most effective and safe way to prevent a cat from going into heat and getting pregnant is through sterilization (ovariohysterectomy – surgical removal of ovaries and uterus). Sterilization for females can start from 6 months of age, and for males, from 10-12 months. The postoperative recovery period is relatively short, around 5-7 days.

Can I Give My Cat Pills to Stop Heat?

It is not recommended. hormonal preparations (injectable or pill treatments) that stop heat in cats are not recommended because they cause severe hormonal imbalances in their bodies and can contribute to the development of ovarian cancer, mammary tumors, ovarian cysts, and uterine infections (pyometra). Other adverse effects include lethargy, behavior changes, vaginal discharge, vomiting, diarrhea, tremors, and frequent urination. They can predispose to viral diseases and hepatotoxicity.

Should I Let My Cat Have a Pregnancy Before Sterilization?

No. It is just a myth. It is not healthier for the cat to have a birth first; on the contrary, it can predispose your cat to health problems (both for the mother and the kittens) and contribute to the excessive growth of the cat population. Early sterilization is the best option for the health and well-being of the cat.

Source: personal arhive

Can a Cat be Sterilized When in Heat?

Yes, it is possible, with the note that it is not recommended. During the heat period, the uterus undergoes the most profound changes under the influence of ovarian hormones. The wall is much thickened and vascularized, and much more fragile, so sterilization during this period involves much greater risks (tissue ruptures, excessive bleeding). There is a risk of infection because, during heat, the cat’s vaginal tissue becomes more edematous and vascular, predisposing to postoperative infections. The recovery time is prolonged. The heat period predisposes the cat to considerable physiological stress, over which surgical stress and anesthesia stress overlap, affecting the healing and recovery process.

The general recommendation is to sterilize the cat 7-10 days after the characteristic signs of the heat period have subsided or at any other time when she is not in heat to minimize surgical risks and facilitate a faster and complication-free recovery.

It is important that a preoperative consultation be conducted by the veterinarian before sterilization regarding the necessary investigations and to choose the most suitable time for sterilization based on the patient’s age and clinical condition.



  1. Diaconescu, A., Bîrțoiu, A. (2009) – Noțiuni de fiziologie a reproducției la mamiferele domestice. Ed. Curtea Veche
  2. https://www.petmd.com/cat/care/evr_ct_cat-facts-how-long-are-cats-in-heat