Females in heat often cry incessantly, show nervous behavior, and attract unwanted male animals. Spayed and neutered pets are less likely to bite. Unaltered animals often exhibit more behavior and temperament problems than those that have been spayed or neutered. Spaying female dogs and cats eliminates the possibility of uterine or ovarian cancer and greatly reduces the incidence of breast cancer. Neutering male dogs and cats reduces the incidence of prostate cancer.
Neutered animals are less likely to roam and fight.
Irresponsible breeding contributes to the problem of dog bites and attacks. Animal shelters are overburdened with surplus animals.