Cats should be at least 8 weeks old before they are neutered. However, kittens 8 weeks old or older that remain under 2 pounds should be allowed to first reach a proper weight to lower the risk of possible medical complications from the procedure.
Early neutering is recommended for a number of medical reasons. Cats that are neutered young have a decreased risk of cancer. They are less likely to suffer surgical complications than older animals undergoing the procedure. After neutering, cats are less likely to spray urine or fight with other cats, as these are territorial behaviors associated with competition for sex.