Glossary

Neuter

The surgery that removes a male cat's testicles so he cannot father kittens, with fewer urges to roam, fight and spray.

Also called: neutering, castration, castrate, fixing a male cat

Neutering a male cat means removing both testicles under general anesthesia. It is a short operation, and most cats go home the same day. The word neuter is also used for both sexes, but for a female cat the usual term is spay.

An entire tomcat tends to roam, fight, mark territory with strong-smelling urine and call for females. After neutering those behaviors usually fade, though not always, and some habits already learned may continue. Fewer fights mean fewer bite abscesses and a lower chance of catching viruses such as FIV that spread through bites. Neutered cats can still develop a urinary blockage, so the surgery does not remove that risk.

Many vets operate from around four to six months of age, and some shelters neuter kittens earlier. A cat whose testicles have not descended needs a longer procedure, see cryptorchid. Aftercare is simple: keep the cat indoors and calm for a few days, stop it licking the wound, and check the site daily. Call your vet if the wound is open, swollen or leaking, or if the cat seems unwell. Neutered cats burn fewer calories, so ask your vet how to avoid obesity.

Last reviewed November 7, 2026

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Related terms

Spay The surgery that removes a female cat's ovaries, and usually the uterus, so she can no longer become pregnant or go into heat. Cryptorchid A male cat with one or both testicles that have not moved down into the scrotum, staying in the groin or abdomen. Anesthesia The medically controlled loss of consciousness and pain sensation that lets a vet perform surgery, dental work or imaging safely. Urinary blockage A life-threatening emergency in which the urethra is plugged so a cat cannot pass urine, most often in male cats. Cat bite abscess A pocket of pus under the skin that forms after a bite or scratch from another cat, common in outdoor, unneutered males. Obesity Excess body fat that harms a cat's health, raising the risk of diabetes, arthritis and urinary disease.

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