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What Are the Possible Complications of Neutering a Cat?

Kristie Leong M.D. is a family practitioner with a strong background in nutrition.

Neutering a male cat, also known as castration, is a simple surgery that involves removing the testicles of a male cat, so it can’t impregnate a female cat and produce kittens.

Neutering a cat helps to reduce the problem of pet overpopulation, but some pet owners still worry about the potential risks of neutering the family cat. Some fear their pet will experience complications, and others worry that it will change their cat’s basic personality.

If you have a cat and are considering neutering them, what are the risks? What are the potential complications of neutering a cat?

Is Cat Neutering a Safe Surgery?

Removing the testicles from a male cat is a straightforward procedure with a low fatality rate. In a healthy cat, the risk of dying during the procedure is about 1 in 1000, although it can be as high as 1 in 75 in animals that already have medical problems.

Veterinarians neuter cats under general anesthesia—and anesthesia always involves some degree of risk. Fortunately, it’s rare for cats to have allergic reactions or other problems related to the anesthetic agents if they’re closely monitored during the procedure.

After neutering, there’s also the risk of bleeding and a small risk of infection. Some of the risks can be reduced by ensuring your cat is healthy before going on the operating table – and they haven’t eaten before the procedure.

If a cat eats prior to surgery, they could vomit while under anesthesia. They could aspirate some of their vomit, leading to aspiration pneumonia. Always follow your veterinarian’s instructions on withholding food and water before surgery.

After Being Neutered, Does a Cat's Personality Change?

Removing the testicles of a cat reduces male hormone levels. This means they’re less likely to roam in search of a female cat. As a result, a neutered cat is more likely to hang around home.

Some owners who have had their cat neutered say they’re more docile, but dramatic personality changes are uncommon. There are benefits too. Neutered cats are less likely to fight or be aggressive toward other cats.

Some neutered cats gain weight after they’re neutered. The decrease in male hormones may alter their metabolism and appetite – or it may be the lower level of activity after neutering that accounts for the weight gain.

One study found that appetite hormone levels rise in cats after neutering and this leads to increased appetite and food consumption. The best way to prevent weight gain is to feed your cat a healthy diet that doesn’t contain too many calories and ensure they get physical activity daily.

Other Possible Complications

Neutered cats have a greater risk of urinary tract problems including problems with stones and blockage of their urethra—and urethral conditions that cause incontinence.

Some, but not all, literature shows that neutering a cat reduces the anima's risk of prostate cancer and eliminates a cat’s risk of getting testicular cancer. Those are compelling arguments to consider neutering a cat.

What about longevity benefits? There is some evidence that neutered cats live longer. This may be due to their lower risk of some types of cancer—or it may be because they’re less likely to roam the streets where they could be killed or injured.

Plus, neutered cats are at lower risk of developing feline leukemia virus or feline immunodeficiency virus which are harmful to cats and can shorten their lifespan. So, there are health benefits to neutering.

Is It Worth the Risk?

Reducing the risk of pet overpopulation and the tendency to roam are reasons to consider neutering a male cat, but it’s important to discuss the risks with your veterinarian first. Cats that are healthy and at low risk of complications or death from neutering will likely sail through the procedure and recover quickly.

But if your cat has medical issues, like heart or lung problems, they’re at higher risk of complications from any surgery. Consider the pros and cons and discuss them with your veterinarian carefully before scheduling the surgery.


This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.