To remove a male cat's testicles by castration so it cannot reproduce. Neutering is the only effective way to reduce the number of unwanted cats worldwide. It is recommended that pet cats are neutered at four months of age or younger, before they start puberty, to prevent unplanned pregnancies.
- Control of nuisance. Unneutered male cats are likely to stray over a large area, will mark their territory with a very pungent spray and are much more likely to fight - with attendant noise nuisance.
- Health issues. Fighting males are much more likely to spread diseases such as FIV and FeLV to other cats. They are also likely to suffer from fight injuries such as abscesses. Because they wander over a large area they are also at greater risk of suffering road traffic accidents.
- Pet issues. Unneutered male cats will wander from home and may not return. They may also spray inside the home and may be aggressive to their owners. Therefore it is desirable to neuter kittens early enough to ensure that the above problems are prevented. Most people do not want to live with an unneutered male cat.
- Population control. Obviously male cats do not have kittens themselves and it only takes one male in an area to make lots of female cats pregnant, so neutering a female cat makes a great deal more difference to limiting numbers, but it all helps!
- Main article: Spaying