COVID-19 Update: AAHA staff is currently working remotely and will support our members virtually. All orders are currently shipping as normal.
Click here for more information.

When should I spay or neuter my pet?

As part of the battle against pet overpopulation, it used to be common practice to spay and neuter young pets as soon as it was safe to do so, and sterilization still is routinely performed on shelter puppies and kittens. When it comes to privately-owned pets in secure homes, here are AAHA’s most recent recommendations.

  • Cats: Female kittens can enter their first heat cycle as young as four months, but usually not until they are five or six months old. AAHA has endorsed the “Fix Felines by Five” initiative, which recommends sterilization of cats by five months of age. This recommendation prevents unwanted litters and greatly decreases mammary cancer risks in female cats as well as spraying/marking in male cats, but still allows kittens time to grow. Kittens sterilized at this age quickly bounce back from surgery.
  • Dogs: According to the AAHA Canine Life Stage Guidelines, small-breed dogs (under 45 pounds projected adult body weight) should be neutered at six months of age or spayed prior to the first heat (five to six months). Large-breed dogs (over 45 pounds projected adult body weight) should be neutered after growth stops, which usually is between 9 and 15 months of age. The decision on when to spay a large-breed female dog is based on many factors—your veterinarian can help narrow down the recommended window of 5 to 15 months depending on your dog’s disease risk and lifestyle.

What are the benefits of spaying or neutering my pet?

Many pet owners think their female pet needs to experience the joy of motherhood at least once or that their male pet will feel less masculine if he’s neutered, but animals simply do not think that way. US pet owners choose not to spay or neuter their pets for a variety of reasons, including:

  • They show or breed the animals
  • Financial constraints
  • Fear of anesthesia
  • Lack of understanding of the benefits

These concerns might seem valid, but the reasons to spay or neuter far outweigh the risks of not doing so. Older show or breeding pets who are spayed or neutered can avoid various cancers and infections. Many spay-and-neuter clinics are low-cost and anesthesia in veterinary medicine now is on par with human medicine. If you’re still not convinced that spaying or neutering your pet can lead to a happier, healthier, longer life, consider these benefits:

  • Spaying your female pet drastically slashes her risk of mammary cancer, which is fatal in about 50% of dogs and 90% of cats.
  • Neutering your male pet eliminates his risk of testicular cancer.
  • Spaying and neutering limits pet overpopulation.
  • Spaying your female pet prevents heat cycles and eliminates yowling, crying, erratic behavior, and bloody vaginal discharge.
  • Neutering your male pet reduces inappropriate behaviors, such as roaming to find a mate, marking inside your home, and fighting with other males.
  • Spaying and neutering is more cost-effective than skipping the surgery. A uterine infection that requires emergency surgery to save your female pet’s life easily can cost several thousand dollars, while a simple tomcat neuter costs much less than products needed to eliminate urine odors after your home has been well-marked by your territorial male cat.

What does research show about spaying and neutering pets?

There is little data concerning the correct age to spay and neuter pets, but emerging research informs AAHA’s guidelines. For example, cancer, orthopedic disease, behavioral problems, endocrine disorders, obesity, and urinary incontinence may be linked to sterilization status and the age at which the procedure is performed. The University of California, Davis, conducted a study on golden retrievers in 2013 that turned the world of veterinary medicine on its head concerning early spaying and neutering. Early sterilization prevented many issues, according to the study, but also appeared to increase the risk of other diseases, such as cranial cruciate ligament rupture, hemangiosarcoma, mast cell tumors, lymphosarcoma, and hip dysplasia. More research is needed, especially with different canine breeds, to help us understand the cause and effect of sterilization and the relationship between spay/neuter status and disease prevalence. More studies on the link between sterilization age and the onset of certain diseases also are needed.

The decision about when to spay or neuter your pet is one you should make with your AAHA-accredited veterinarian. She is your most up-to-date resource, and her knowledge of your pet’s particular breed and potential disease risk can help you make an informed decision about the appropriate age for your pet’s sterilization.