When male kittens reach puberty, their behavior will begin to shift and one of the favorite pastimes of maturing male cats is marking their territory with urine. VCA Animal Hospitals reports that castration can put a stop to this behavior, but the longer a tomcat is allowed to act this way, the less likely the procedure will be effective in curbing the behavior.
Outdoor cats may need to be neutered to prevent them from getting into fights to protect their territories and establish dominance. Unless there are multiple male cats in a residence, indoor cats will likely not have this issue.
There are health advantages to having your tomcat neutered, as well. The ASPCA reports that removing the testicles can reduce the risk of injuries and disease transmission that could result in cat illness, since neutered cats will be less likely to fight other felines. This procedure also eliminates the chances of your cat developing testicular cancer.
Puberty typically sets in between six and 10 months, and VCA recommends having the surgery performed when a cat reaches five to seven months.