Other health problems

Can Spayed Cats Go Into Heat?

María Besteiros
By María Besteiros, Expert veterinary assistant and canine/feline hairdresser.. Updated: May 16, 2024
Can Spayed Cats Go Into Heat?

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By definition of the procedure, spayed cats should not be able to go into heat. Spaying females and castrating males means their reproductive organs are removed which produce sex hormones. For females, this means their ovaries and uterus in the most common procedures. Their removal should stop the heat period occurring because they lack the ability to produce the hormones which commence it. This is due to the many benefits for the individual cat, both physically and behaviorally. The reduction of unwanted pregnancy also helps cat populations in general. For this reason, a spayed cat going into heat seems like an impossibility.

At AnimalWised, we find out can a spayed cat go into heat? We look at the possible reasons for this circumstance and what we will need to do about it.

You may also be interested in: Do Rabbits Go Into Heat?
  1. Can spayed cats go into heat?
  2. Why do spayed cats go into heat?
  3. Reasons spayed cats go into heat
  4. Treatment of heat in spayed cat
  5. Can you spay a cat in heat?

Can spayed cats go into heat?

If we think our spayed cat is behaving abnormally, we need to determine if these are symptoms of the heat period or another problem. Female cats will be sexually mature from around 6 months of age. After this point, the cat will be seasonally polyestrous, meaning they can have multiple heat cycles during the breeding season. This season is generally between January to October.

Cats in heat will want to seek out a male for mating purposes. Hormonal changes in the cat drive their behaviors and they will experience various changes during the heat period. When a cat is in heat, we should see:

  • High-pitched meowing which the cat performs to draw attention from local male cats.
  • Restlessness which can lead to nervousness and anxiety.
  • Lifting of tail to expose genitals.
  • Rubbing against people or objects, specifically their rear area, to relieve frustration.

Domestic cats do not exist in the same way as their wild or feral counterparts. They have their needs provided for by their human guardians and procreation is not encouraged due to the already problematic high cat populations. Additionally, spaying can help improve their health as it prevents the development of certain health problems, especially uterine diseases (such as feline pyometra and uterine cancer).

Spaying is designed to remove the sex organs in female cats which would have otherwise produced the sex hormones which instigate the heat cycle. While some variations occur, it is most common for cats to be given an ovariohysterectomy whereby both the uterus and ovaries are removed. These tissues produce the vast majority of sex hormones in the cat.

With this in mind, a spayed cat should not be able to go into heat. However, in very rare cases, there may be spayed cats which show signs of heat. If your cat displays signs of heat after they have been spayed, we will need to take them to a veterinarian for confirmation. Since it is possible other diseases can lead to physical and behavioral problems such as meowing more than usual, we need to confirm a diagnosis.

The veterinarian will likely perform a cytology by taking a sample from the cat's vagina with a swab. This sample will be analyzed under a microscope to see which cells are present and which indicate the cat is indeed having their heat cycle. It is also possible the veterinarian will draw blood to determine estrogen levels as this is the hormone which can confirm the cat is in heat.

Why do spayed cats go into heat?

If the test has confirmed your cat is indeed in heat, it implies something has gone wrong with the sterilization procedure. Spaying is the term for a specific type of neutering which usually involves the removal of the uterus and both ovaries. As stated above, it is also known as an ovariohysterectomy.

It is recommended a female cat is spayed before they enter their first heat, when they are around 5 months of age. The reason for this is to provide the maximum benefit to the cat. If they are spayed after they reach sexual maturity, they are more likely to have behavioral issues associated with sexual maturity. The surgery is performed under general anesthetic and involves a small ventral incision through which the ovaries and uterus are removed. When only the ovaries are removed, it will likely be a lateral incision.

During surgery, the veterinarian ensures that no remnants of tissue remain. They will suture the incision with stitches or staples. Analgesic and antibiotic treatment may be administered, but not in all cases. Guardians need to ensure the wound is cared for so that it does not develop a secondary infection or re-open. The cat will return to their normal selves after around 24 hours, although they may require an e-collar to prevent them licking their stitches. This related article shows you how to make an e-collar at home.

After approximately one week, the stitches are removed and the cat should live a normal and happy life. We shouldn't have to worry about them going into heat which is why it can be disconcerting if we see our spayed cat enter their heat cycle.

Can Spayed Cats Go Into Heat? - Why do spayed cats go into heat?

Reasons spayed cats go into heat

When cat enters heat after being spayed, the problem is likely due to the surgery not being completely successful. However, there are some other reasons why a cat will have symptoms of heat after being spayed. They include:

  • Ovarian remnant syndrome (ORS): when some tissue of the ovaries remains post-surgery, it is possible the cat can still produce hormones which lead to inducing the heat cycle. This is not necessarily due to malpractice. For anatomical reasons, it will be difficult to perform a complete extraction. It is always important to look out for post-surgical complications in cats, even if they are rare.
  • Ectopic ovarian tissue: another aspect of ovarian remnant syndrome might not be due to surgical error. Sometimes ectopic ovarian tissue can use only a few cells to activate the hormone cycle produced during the heat period in cats. It is even possible for the remaining tissue to attach in the peritoneum and become functional.
  • Pyometra: pyometra can occur if the ovaries are removed, but not the uterus, or if there are uterine remnants. In these cases, the residual tissue becomes infected and it can result in stump pyometra. This infection needs to be activated by hormones controlling the estrous cycle.
  • Other hormonal issues: if your cat has ingested estrogen for whatever reason, it is possible it will initiate their heat cycle. For example, topical pills or creams which contain this hormone may be consumed if left round the home. Tumors on the adrenal glands can also affect the production of estrogen, resulting in the cat going into heat after being spayed.

The release of hormones can also result in something known as phantom pregnancy in cats. This is when the cat believes they are pregnant due to the hormonal changes, even though no fetuses are gestating. While the above reasons can lead to a spayed cat going into heat, it is important to note this is very rarely recorded in felines. The highest recorded instance is of surgical error[1], but treatment is available.

Treatment of heat in spayed cat

Once the diagnosis has been confirmed by a veterinarian and other medical problems have been ruled out, treatment will most likely involve surgical intervention. With ovarian remnant syndrome, the remnant tissue will need to be removed. This will happen with an exploratory laparotomy, a procedure similar to the initial ovariohysterectomy. This is also the case with stump pyometra as the infected tissue will be removed.

There are some hormone treatments in the form of progestogens, but these are unlikely to be administered. This is because they have serious side effects which include the development of mammary tumors or even inducing stump pyometra. If the ingestion of estrogen has lead to the inducement of heat, then it should stop once they are no longer ingested.

Adrenal tumors and other problems which lead to hormonal changes will need to be treated individually. These may require surgery or even chemotherapy, with the resultant heat symptoms being secondary issues. Once they are treated, the cat should return to normal.

Can you spay a cat in heat?

There are some rare occasions when a cat will be spayed if they are showing heat symptoms. Usually, the veterinarian will wait until the heat symptoms have finished before performing the procedure. In cases where the cat's health is in danger, it may be better to perform surgery if the benefit to the cat is greater than the risk. To know when this will be, find out how long a cat will be in heat.

For cases where further surgery is required (as is the case with exploratory laparotomy), it might be better to perform surgery to reduce the risk to the cat's health. This will be determined by the veterinarian.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Can Spayed Cats Go Into Heat?, we recommend you visit our Other health problems category.


1. Ball, R. L., et al. (2010). Ovarian remnant syndrome in dogs and cats: 21 cases (2000-2007). Journal of the American Veterinary Medical Association, 236(5), 548-543.

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1 comment
Jennifer minniti
15 yr old female spayed cat has sudden onset of symptoms of being in heat?
Administrador AnimalWised
Hi Jennifer,

This could be anything from an environmental change or neurological deterioration as is common in senior cats. Please speak to a veterinarian for diagnosis.
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Can Spayed Cats Go Into Heat?