According to the Humane Society of the United States, "an estimated 3 to 4 million cats and dogs are euthanized in shelters yearly. The average female cat has three litters per year with four to six kittens per litter. In seven years, one female cat and her offspring can theoretically produce 420,000 cats." Spaying and neutering can decrease these numbers and create healthier cats.

Both proced ures involve general anesthesia. During a neuter, the male's testicles are surgically removed from the scrotum. During a spay, the female's ovaries and uterus are surgically removed from the abdomen. Males usually recover more quickly than females, and kittens tend to bounce back more quickly than adult cats. Decreased activity for a day or two after surgery is common.

Heather Weir, DVM, head of the spay/neuter program at Colorado State University in Fort Collins, Colo., recommends spaying or neutering a kitten at 4 months of age, once its vaccines are finished. She cites many advantages to the surgeries, including decreasing reproductive cancers and uterine infections, decreasing spraying by toms and reduced roaming in both sexes. Weir also warns that cats come into heat very quickly and can get pregnant while still nursing a litter.

For more information on the benefits of spaying or neutering your kitten, visit the American Veterinary Medical Association's Care for Animals website (look under "Site Index" for "Spaying and Neutering FAQs").