When should I spay or neuter my pet?

It used to be common practice to spay and neuter young pets as soon as it was safe as part of the battle against pet overpopulation, and sterilization is still 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 the birth of unwanted litters and greatly decreases mammary cancer risks in female cats and spraying/marking in male cats, but still allows kittens time to grow. Kittens sterilized at this age bounce back quickly 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 is usually between 9 and 15 months of age. The decision on when to spay a large-breed female dog is based on many factors, and 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 routinely forgo spay and neuter surgeries for their pets for a variety of reasons, including the following:

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

While these concerns may seem valid, they can be dispelled. Older show or breeding pets who are spayed or neutered can stave off various cancers or infections. Many spay and neuter clinics are low cost, and anesthesia in veterinary medicine is now on par with human medicine. If you’re still not convinced that spaying or neutering your pet can lead to a happier, healthier, and 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 prevents contributing to 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 everything inside your home, and fighting with other males
  • Spaying and neutering is more cost effective than forgoing surgery. A uterine infection that requires emergency surgery to save your female pet’s life can easily cost several thousand dollars, while a simple tomcat neuter costs much less than the products needed to eliminate urine odors in your home that’s been well marked by your territorial male cat

What does research show about spaying and neutering pets?

Research studies concerning the correct age to spay and neuter pets are few, but they have informed AAHA’s guidelines. Cancer, orthopedic disease, behavior, 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 and neuter status and disease prevalence. More studies on the link between sterilization age and the onset of certain diseases are also needed.

The decision 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.