Neutering your pet will prevent him or her from reproducing and adding to the pet overpopulation problem. It also offers numerous health benefits, even if your dog or cat is confined and never allowed to come into contact with other animals.
Spaying, which is the removal of the entire uterus and both ovaries in a female animal, will protect her from potentially fatal uterine infections and tumors. It also drastically reduces the incidence of breast cancer.
Castration, the removal of the male's testicles, reduces the incidence of roaming, mounting, urine marking, and aggression with other males. Your male pet, once neutered, will be less likely to fight with other animals or to get hit by cars while roaming around looking for a date. Neutered males are also much less likely to develop prostate disease and some types of tumors.