Updated March 8, 2019: There are two big reasons people don’t spay and neuter their cats: 1) it’s too expensive and 2) they have misconceptions about the procedure.
Let’s get the "expensive" part out of the way. Most vets offer spaying and neutering for about $100. If you can’t afford that, there are low-cost spay/neuter programs across the country — ASPCA keeps a database of low-cost programs that you can use to search for a resource in your area.
For a lot of pet owners, $100 will be a small price to pay when you consider the benefits (which we’ll get into below). But if you’re facing a situation where $100 is still too much, there are resources out there for cat owners who need a low-cost solution.
Low-cost solutions are also useful if you want to help control the stray cat population in your area. Trap and release programs (see below) rely on low-cost spay/neuter programs to work because the cats don’t have any human to take on the financial cost of their surgery.
Benefits of spaying/neutering your own cat
Male and female cats are less likely to get cancer
Spaying your female cat helps reduce the risk of uterine or breast tumors, which, according to ASPCA, are cancerous in 90% of cats. Basically, spaying your female cat crosses a big disease off of the "ways to die" list, or at least moves it to the bottom.
Neutering a male cat offers similar protection from testicular cancer and prostate problems.
Your cats will be better behaved
Both male and female cats do ridiculous stuff when hopped up on hormones. Female cats, for example, howl and urinate everywhere when they go into heat, which is an absurd way to try to get a mate. Male cats urinate everywhere, too. In general, feline mating rituals make Tinder look a lot more civilized.
Neutering your male cat can also help curb aggression problems. In fact, if you ever watch My Cat From Hell, possibly the best Animal Planet show, you’ll see cat behaviorist Jackson Galaxy tell cat owners to spay/neuter their insane cats almost every episode.
It’s cheaper than raising kittens
Raising an entire litter of kittens is expensive — once you add up medical costs, you can find yourself easily spending hundreds of dollars before those cats leave your door. Plus, consider the countless hours it takes to get those kittens ready for the real world.
Misconceptions about spaying/neutering
You need to let your female cat have a litter before spaying her
You don’t. In fact, if you wait to have your cat spayed until after she goes into her first heat, you actually increase her risk of uterine cancer. Plus, the world doesn’t need more kittens — there are millions of shelter cats waiting to be adopted right now.
You can’t alter a kitten
You can totally alter a kitten. As long as the cat is eight weeks old and weighs at least two pounds, you can have your kitten spayed or neutered. In fact, that’s really the best time to do it. If you wait until their hormones start going crazy, you miss out on some huge potential medical and behavior benefits of altering.
Cats get super fat after you alter them.
Neither spaying nor neutering will have a long term effect on your cat’s weight. If your cat is getting fat, it’s up to good ol’ fashioned portion control to save the day.
Trap-Neuter-Release (TNR) Programs
Spaying and neutering isn’t just beneficial for cats that have a home. It’s also incredibly important to help control the feral cat population.
Feral cats can be a menace to the community. When they go out looking for mates, they can cause a ruckus in residential areas and disturb other cats. They also get into fights with outdoor house cats.
Feral cats are not the same as stray cats. Stray cats had a home at some point and, under the right circumstances, can become a housecat again. Feral cats have never been socialized to humans and it is highly unlikely that they will become pets.
So what’s the solution? If feral cats are menaces when they’re wild but can’t be tamed by adoption, how do we figure out a humane solution?
One answer is trap and release programs, also called trap-neuter-release (TNR) programs. Basically, if you alter feral cats, their behavior calms down a lot, and it reduces their population in the future. ASPCA is a fan of it, calling it the "most humane, efficient way of stabilizing community cat populations."
If you’re looking to control a community cat population, look for low-cost spay/neuter programs or talk to a vet in your area about helping you out with costs. You may be able to form a coalition among your neighbors to share the cost of controlling the cat population. For more advice on starting your own TNR program, check out Alley Cat Allies, a non-profit organization dedicated to the humane treatment of cats.