For decades, Bob Barker ended every episode of “The Price is Right” with these words: “Help control the pet population. Have your pets spayed or neutered.” But spaying or neutering your pet doesn’t just reduce the number of unwanted pets in animal shelters. It benefits your pet’s health, too.

Spaying, which means removing the ovaries and uterus of a female cat or dog, and neutering, which means removing the testicles of a male cat or dog, is a routine veterinary procedure. Recovery takes a few hours for male pets and less than a day for females. 

"Fixing" (spaying or neutering) your pet will improve your pet’s behavior and well-being, experts say.

Related: How to Choose the Best Dog for Your Kids

Less spraying and humping

Cats that aren’t fixed tend to spray and urinate to mark their territory. If they get outside, they are prone to fighting. That changes when a cat is fixed. “For cats, there’s a reduction in spraying and inappropriate urination and fighting,” says Patricia Patterson, DVM, staff veterinarian at Best Friends Animal Society. “Fixing a dog reduces behavioral problems such as aggression, roaming, marking and humping.”

Patterson notices thatspayed/neutered pets are often a bit calmer. “There not as distracted and therefore they are easier to train and are more mindful of commands,” she says.

A reduced risk of cancer

“Spaying/neutering cats and dogs reduces the chance of hormone-related cancers such as mammary cancer, uterine/ovarian cancer, testicular cancer, perianal adenomas [in dogs] and contagious cancers such as transmissible venereal tumors. It reduces the risk of perianal hernias and infections such as pyometras,” Patterson says. “It also makes diseases such as diabetes and Addison’s disease [which can occur in dogs] much easier to treat and control.”

Related: 13 Health Symptoms Dog Owners Should Never Ignore

When to spay or neuter

Kittens and puppies can have their first heat cycle as young as four months. So it is important to spay/neuter them before that time. Your pets can be fixed between four and eight weeks. It’s a decision you should discuss with your pet’s veterinarian.

And yes, it’s good for the animal population

In the 1970s, animal shelters euthanized as many as 11 million cats and dogs a year. Thanks to education by animal shelter workers, humane organizations and veterinarians, that number is  now between 2 and 3 million, according to the American Society for the Prevention of Cruelty to Animals.

2 myths debunked

The most common one is that your cat or dog will get fat after being fixed. A lack of exercise and too much food may pack on the pounds, but fixing your pet won’t, according to the Humane Society.

Another myth is that the procedure is expensive, but it doesn’t have to be. Many animal shelters and rescues offer low-cost surgeries.

Related: 10 Ways to Care for Your Pet on a Budget

Michele C. Hollow writes about pets and wildlife. She is an award-winning journalist who has written for The New York Times, The New York Daily News, and other leading publications. She blogs at Pet News and Views.