Benefits of Spaying and Neutering

This information is provided for general animal health education purposes only. Specific advice on diagnosing or treating an animal health care problem should be obtained from a veterinary care provider. For a list of veterinary services at the University of Minnesota, see About the Medical Center.

Written by Teresa Hershey, D.V.M.

Spaying

General information
Ovariohysterectomy is the medical term for spaying a female cat or dog. The procedure consists of removing the ovaries and uterus.

Benefits of spaying

• Prevents unwanted litters
• Eliminates heat periods
• Eliminates the risk of your pet developing a life-threatening infection of the uterus called a pyometra.
• Reduces the risk of mammary (breast) cancer. In dogs, a female spayed before her first heat will have a near-zero chance of developing mammary cancer. After the first heat, this incidence climbs to 7 percent, and after the second heat, the risk is 25 percent. If your pet has already gone through one or more heats, we still recommend spaying. Spaying can help shrink mammary cysts and prevents pyometra.

When to spay
We recommend that cats and dogs be spayed before their first heat, generally at about six months of age.

Neutering

General information
Castration is the medical term for neutering your male cat or dog. The procedure consists of removing the testicles.

Benefits of neutering

• Prevents unwanted litters
• For dogs:
• Prostate health
• Neutering helps shrink enlarged prostate glands, which can be uncomfortable and can become large enough to interfere with defecation.
• Neutering helps to prevent infection in the prostate.
• Other health benefits
• Neutering helps prevent inguinal hernias.
• Neutering helps prevent tumors of the anus.
• Neutering eliminates the possibility of testicular cancer.
• Excessive discharge from the penis is reduced after neutering.
• For cats:
• Neutering helps decrease behaviors, that, although normal in the cat, humans find unacceptable.
• 90 percent of neutered cats decrease their incidence of urine marking
• 90 percent of neutered cats decrease their incidence of fighting
• 90 percent of neutered cats decrease their incidence of roaming.

When to neuter
Cats: Between 4-6 months
Dogs: Between 6-12 months

Spay/neuter recommendations may change for patients with medical or behavioral problems, or for Humane Society population control programs.