There are numerous reasons you should spay or neuter your cat.
Female cats that are spayed cannot get uterine cancers; their risk of mammary (breast) cancer is reduced by 25%; and they are less prone to urinary tract infections and hormonal changes.
Male cats that are neutered cannot get testicular cancer, and they live 40% longer than their unneutered counterparts. Unneutered male cats respond to the “call of the wild” and their desire to wander is fierce. Unneutered male cats may become aggressive toward other cats, increasing their risk of injury and becoming infected with feline leukemia and/or feline immunodeficiency virus. And don’t forget: unneutered male cats tend to spray urine, which can smell very bad.
Aside from the important medical reasons for spaying or neutering, there is also a serious overpopulation problem in the United States. An average cat has 1–8 kittens per litter, and 2–3 litters per year. During her productive life, one female cat could have more than 100 kittens. A single pair of cats and their kittens can produce as many as 420,000 kittens in just 7 years.2
Over 12 million unwanted dogs and cats are euthanized each year, and even more are abandoned.