Preventing pets from reproducing is the primary purpose of spaying and neutering. This certainly is not the only benefit, though. Spayed female pets are less likely to develop mammary tumors or cancer. They are less susceptible to uterine infections, too. And spaying eliminates the risk of ovarian cancer.
In males, neutering lowers the risk of prostate problems while eliminating the risk of testicular cancer.
Spaying and neutering lower the risk of hormonal problems as well as endocrine disorders, including diabetes. Additionally, these routine procedures often curb problematic behaviors, including aggression, urine spraying, howling, and roaming. They prevent annoying heat cycles, too.