Will spaying or neutering reduce your cat’s aggression?

Will spaying or neutering stop your cat’s aggression? In veterinary practice, it is common to suggest neutering toms whenever they show any kind of aggression. This is probably because neutering a cat is a reasonable thing to do, regardless of how aggressive the cat is.

Aggressive intact male cat
Neutering stops male cats from fighting. Photo © Irina Schmidt

But due to some trivial issues motivated by sensitivity, humane concerns, or pride, neutering or spaying is often questioned by pet owners as unnecessary and “unlikely to work.” What is the truth? Can spaying or neutering a cat really help to reduce its aggression?

ANSWER: It certainly can! While nothing is guaranteed, most cats become significantly calmer after such surgery. However, the real underlying cause of aggression may still have to be addressed.

To be succinct, it depends on what causes your cat’s aggression and what other things you are willing to do.

  • If your male cat is aggressive towards other cats, neutering is an extremely effective way to stop it. Inter-cat aggression is usually territorial or sexual. These types of aggression are primarily triggered by the hormone called testosterone, which is produced in testes. When there are no testes, testosterone levels drop significantly and aggression may disappear as instantaneously as waving a magic wand. However, it isn’t guaranteed. A cat who’s been aggressive for years may have habituated to be one, thus some behavioral and environmental modification will be necessary.
  • Female cats rarely show sexual and hormonally-regulated aggression. The only cases are associated with copulation strategies or when she must defend her kittens. Thus, spaying is not directly related to their aggression levels. But if your female cat is aggressive during her heat cycle, spaying her will stop the misery.
  • Hormones in a cat that attacks people, regardless of its gender, are not the primary cause of its actions. Spaying or neutering will make your cat calmer and tolerate handling better. However, if there is underlying fear, pain, or stress, the surgery alone is unlikely to stop aggression. It helps, but, for example, if your cat attacks you out of fear, he will still be afraid of you after his testes are gone.

Nevertheless, in any case, it’s very hard to stop a cat from being aggressive without fixing them. This is especially true for males.

It is possible to have a non-aggressive, intact male cat if you prevent him from wandering and meeting other males. But to be honest, that is an everyday struggle that should be reserved for cat breeders.

If you have a family pet, spaying or neutering your cat is probably the best thing to do—for both of you.