Neutering offers benefits to both you and your beloved companion. The benefit of neutering a cat? Fewer unwanted litters and fewer parental worries for you.
Neutering (or spaying) is the process by which your cat's veterinarian renders her sterile. When male cats are sterilized, the process is called neutering. When females receive the same treatment, it's called spaying (nonetheless, you can refer to either procedure as neutering).
It's hard to accept, but there aren't enough homes for the cats currently in need of adoption. According to the American Society for the Prevention of Cruelty to Animals (ASPCA), 3.4 million cats enter shelters every year. By neutering your cat, you'll help reduce the overpopulation of this feline community. More importantly, however, spaying and neutering helps your cat live a healthier, longer life.
The Benefits of Neutering & Spaying
Prevents Diseases
Spaying your female cat before her first estrous cycle (going into "heat" or being able to breed) greatly reduces her risk of cervical cancer and eliminates her risk for ovarian cancer. Because removing the ovaries reduces the levels of hormones that encourage the growth of cancerous tumors, spaying reduces your cat's risk of mammary cancer as well.
Keep in mind there are other diseases resulting from natural cat behavior when they mate. Feline leukemia and feline AIDS are two diseases spread through the bites of infected cats to other cats, according to the VCA Hospitals (these diseases are different from human AIDS and leukemia, and cannot be transmitted from cats to people). By reducing your cat's urge to fight over mates and territory, you'll also reduce her chances of contracting these incurable diseases from other cats.
Reduces Fights
Unneutered male cats are driven by hormones to seek mates and defend their territory against intruders. So, two or more unneutered male cats in the same household can spell trouble. Fights tend to break out, especially if there's a female cat in heat nearby. By neutering your cats, you'll reduce their aggressive instincts.

Reduces Risk of Roaming
When female cats go into heat, both her hormones and instincts are urging her to find a mate. And if she's your only cat, she'll try to escape every time you open the door so that she can find one. Remember that males are also driven by hormones and the mating instinct, and will try their best to escape for the same reason. Both males and females are at risk outdoors of being injured as they cross roads and highways to mate. By neutering your cat, you'll reduce this wanderlust and find they're happy to stay put in the safe, comfy spot next to you on the couch.
Cleaner Home
Male cats spray their urine on vertical surfaces to mark their territory. And while the pungent odor of an unneutered cat's urine alerts other males that there's another guy nearby who has claimed the area as his turf, it tells females he's waiting for his opportunity to mate with her. An unneutered male cat in your house can be a messy business. Neutering a cat reduces or eliminates the urge to spray, and if they do, the scent should be much more mild.
Female cats also pass bodily fluids when they go into heat. These fluids also contain scents to alert males that a fertile female is nearby. By spaying your female cat, you'll eliminate the same problem.