Do Female Cats Bleed If Not Spayed?

Female cats that are not spayed go through regular estrous or “heat” cycles, where their bodies prepare for mating and potentially having kittens. During these heat cycles, which occur every 2-3 weeks during breeding season, female cats exhibit behavioral and physical changes as hormones fluctuate to make them receptive to mating.

The Estrous Cycle

The estrous cycle in cats occurs in distinct stages, each marked by hormonal and physiological changes. According to the VCA Hospitals, the typical estrous cycle length is 2-3 weeks.

The stages are:

  • Proestrus – The first stage when estrogen levels rise, lasting 4-10 days.
  • Estrus – The stage when the female cat is receptive to mating, lasting 4-6 days.
  • Interestrus – The end of the fertile period, lasting 7-10 days as progesterone levels increase.
  • Anestrus – The resting stage when sex hormones are at minimal levels, lasting 2-3 months.

VCA notes that older female cats may experience shorter cycles with more frequent periods of estrus. The average cycle length shortens from 14 days or more to 8-10 days by around 8 years of age.

According to research published in PMC, the typical feline estrous cycle can be divided into these main phases – proestrus, estrus, interestrus (diestrus), anestrus, and metestrus. The cycle involves hormonal regulation of ovarian follicle development, ovulation, and corpus luteum formation and regression.

Signs of Heat

There are several obvious behavioral and physical signs indicating when a female cat is in heat or estrus. Behaviorally, cats in heat tend to become much more affectionate and clingy with their owners and other pets. They rub up against people and objects more frequently, engage in excessive grooming, and tend to roll around on the floor frequently showing their belly. Vocally, a cat in heat will yowl persistently and loudly, especially at night, with a mating call that owners describe as loud, annoying, and impossible to ignore (Is Your Cat in Heat: 9 Obvious Signs of Heat in Cats).

Physically, female cats in heat will display swelling and reddening of the vulva, hold their tails to the side, and frequently lick their genital region. They may frequently get into a mating stance with their rear end raised and front half lowered. Owners may also notice a bloody vaginal discharge during estrus, though bleeding is generally light. Overall, the constant behaviors of vocalizing, rubbing, restlessness, and demanding attention are key signs a feline is in heat (Signs of Heat in Cats).

Mating Behavior

When a female cat enters her heat cycle, she becomes very receptive to mating and will actively seek out male cats. She releases pheromones that signal her fertility and will vocalize frequently with loud, attention-grabbing calls. This mating call, referred to as “calling,” is meant to attract potential mates. According to The Spruce Pets, the queen (female cat) will roll around, rub, and present herself to male cats, assuming the mating position with her head down and rear end up.

During this time, the female cat is highly motivated to mate and will be very persistent about leaving the home to search for male cats. This roaming and mating quest can put the cat in danger as she crosses streets and enters other cat territories. It also leads to fights between male cats competing to mate with her. And if the female cat mates successfully, she will likely become pregnant and give birth to unwanted kittens if she is not spayed.

Therefore, the mating behaviors exhibited when a female cat is in heat can pose risks like unwanted litters, injuries from roaming and fights, and stress for the cat and owner. It is recommended to get cats spayed so they do not go into heat cycles and exhibit these distressed mating behaviors.

The Heat Period

The heat period occurs when the queen (female cat) is in estrus and ready for mating. This phase normally lasts 4-10 days in an unspayed cat and occurs every 2-3 weeks until she is bred1. During the heat period, the female cat experiences the following physical changes:

Vulvar swelling occurs as estrogen levels peak right before and at the start of heat. The vulva becomes swollen and soft, and sometimes a small amount of bloody discharge is present. The bloody discharge occurs as the lining of the uterus starts proliferating in preparation for pregnancy. However, the amount of discharge is typically very minor and lasts less than 48 hours2. The queen will also excessively groom her genital area.

Ovulation happens on days 3-14 of the heat period, with most cats ovulating around days 3-5. It is stimulated by the physical act of mating. The ovaries release eggs that will remain viable for fertilization for 1-2 days. If the queen is not bred, the unfertilized eggs will degenerate and be reabsorbed by the body.

After Heat

Once a female cat finishes an estrus cycle, known as being “in heat,” she enters the luteal phase which typically lasts 30-40 days. This is the period after ovulation when the corpus luteum forms and produces progesterone. The increased progesterone levels cause the female cat’s reproductive tract to be unreceptive to mating during this time. She will not allow males to mate with her until her next heat cycle begins. The luteal phase gives the female cat’s body time to reset itself hormonally in preparation for the next heat.


Pseudopregnancy, also known as false pregnancy, refers to when a female cat shows signs of pregnancy even though she has not been bred or is not actually pregnant (PetMD). It occurs because the female cat undergoes hormonal changes that mimic pregnancy after ovulation, regardless of whether fertilization happens.

Some common symptoms of pseudopregnancy in cats include:

  • Enlarged, swollen nipples
  • Mammary gland enlargement and production of milk
  • Increased appetite
  • Lethargy and behavioral changes
  • Nesting behaviors like shredding bedding and vocalizing
  • Mothering behaviors like adopting toys or other objects as “kittens”

These symptoms occur because the progesterone levels remain elevated even though the cat is not actually pregnant. The symptoms usually last 2-3 weeks as the hormones return to normal. Pseudopregnancy can occur in both spayed and unspayed female cats, though it is more common in cats that go through heat cycles.

Risks of Constant Heat Cycles

Female cats that are not spayed face risks from the constant cycle of coming into heat and hormonal fluctuations. Unneutered female cats are at high risk for developing reproductive cancers or infections later in life. Studies show that 84% of cats that develop mammary tumors are unspayed females. Mammary cancer is aggressive and can metastasize to other parts of the body. Unspayed cats also face a high risk of uterine infections or pyometra, which can be life threatening if untreated.

The constant hormonal fluctuations that accompany heat cycles and pseudopregnancy can also cause anemia and other blood disorders in female cats over time. Studies show the risk of anemia is seven times higher in unspayed female cats. The risk of urinary tract infections also increases in unspayed females. Spaying female cats eliminates these risks by removing the uterus and ovaries and stopping the hormonal cycles that lead to disease.

Consider Spaying

Spaying a female cat provides several health and behavioral benefits. Spaying eliminates the risk of ovarian and uterine cancer and greatly reduces the chance of mammary cancer according to the ASPCA ( It also prevents pyometra, a potentially fatal uterine infection. In addition, spaying eliminates heat cycles and the constant crying and nervous behavior that comes with them.

Spaying may also curb unwanted behaviors associated with mating drives according to the Humane Society ( These include urine marking, humping, and roaming to find mates. Spayed cats are generally calmer, friendlier, and more affectionate.

While spaying surgery does carry risks, veterinarians minimize complications by using modern techniques and monitoring cats after surgery. Most cats recover fully within 10-14 days. The benefits of spaying far outweigh any temporary risks for most cat owners.


In summary, unspayed female cats go through heat cycles approximately every two to three weeks during breeding season. This involves increased vocalization, rubbing, rolling, and attempts to escape outdoors to find a mate. While not life-threatening for most cats, constant estrus cycling can be stressful and increase risks of certain cancers. To avoid repeat heat cycles and pseudopregnancies, pet owners should consider spaying their cats. Consult your veterinarian to discuss the right age and procedure for your feline companion. With professional guidance, spaying can greatly benefit your cat’s health and quality of life.

Scroll to Top