Spaying or neutering your pet is important for their health and to increase their longevity, but determining when to schedule the procedure can be confusing. Our Neighborhood Veterinary Centers team wants to help by providing information about the procedures and guidelines for determining the best time to spay or neuter your pet.

Pet spay and neuter history

The approach to spaying and neutering pets has changed through the years. The following is a brief history about the procedures and what has led to our current recommendations:

  • 1930s — Livestock sterilization had been commonplace for some time, but spaying and neutering pets became more accessible in the 1930s.
  • 1969 — The first low cost spay and neuter clinic opened in Los Angeles, and the number of interested people formed a four-month waiting list.
  • 1979 — In 1973, the Humane Society estimated that 13.5 million dogs and cats were euthanized in the United States. Bob Barker, a television game show host, began advocating for spaying and neutering to help control the pet population.
  • 1990’s — Research in veterinary pediatric surgery and anesthesia protocols allowed veterinarians to perform spay and neuter procedures on much younger pets. Previously, the procedures had been recommended for pets 6 months of age, but new research allowed veterinarians to perform the procedures as early as 6 weeks of age. This was especially helpful in shelters, because pets could be sterilized before leaving the shelter to prevent unwanted litters. 
  • 2013 — A study on golden retrievers suggested that early spaying or neutering may increase the pet’s risk for certain conditions.
  • 2019 — Approximately 920,000 shelter pets were euthanized, significantly down from the 13.5 million euthanized in 1973, proving the value of spay and neuter procedures in helping decrease the pet population.
  • 2020 — New research demonstrated that some large dog breeds may benefit from delayed spay or neuter procedures.

Pet spay and neuter benefits

In addition to helping control the pet overpopulation problem, spay and neuter procedures have many benefits for you and your pet, including:

  • Increased pet longevity — A Banfield Pet Hospitals study demonstrated that neutered male dogs live 18% longer, spayed female dogs live 23% longer, neutered male cats live 62% longer, and spayed female cats live 39% longer.
  • Preventing pyometra — Pyometra is a life-threatening uterine infection that commonly occurs in female pets in the weeks following estrus (i.e., heat). Spaying your pet removes her uterus and prevents this concerning issue.
  • Reduced mammary cancer risk — Spayed female pets have about 90% less chance of developing mammary tumors.
  • Fewer prostate issues — Testosterone causes an unneutered dog’s prostate to enlarge, and by 5 years of age, their prostate can become uncomfortable and more infection-prone. Neutering causes the prostate to shrink.
  • Fewer unwanted male pet behaviors — Neutering reduces or eliminates unwanted behaviors, such as territorial aggression, mounting, urine-marking, and roaming, in the majority of male pets.
  • Preventing heat cycles — Spaying your female pet prevents heat cycles, which are typically accompanied by a messy, bloody vaginal discharge, excessive vocalization in cats, and male pets frequenting your doorstep.

Early pet spay and neuter concerns

Research has demonstrated that early spaying or neutering puts certain dog breeds at higher risk for several concerning issues, including:

  • Joint disease — Puberty initiates hormonal changes that facilitate epiphyseal plate closure on long bones. When certain pets are spayed too early, their long bones grow beyond the intended length, interfering with the normal joint-bone mechanical relationship. This leads to orthopedic problems, such as cranial cruciate ligament disease, hip dysplasia, elbow dysplasia, and patellar luxation.
  • Cancer — Although the reason is unclear, studies have demonstrated that certain dog breeds spayed or neutered early are at higher risk for certain cancers, including lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma.

Pet spay and neuter guidelines

So, when is the best time to spay or neuter your pet? Every pet is unique, and their specific situation must be considered, so it’s best to consult veterinary professionals when making this decision. General spay and neuter guidelines include:

  • Female cats — Female kittens should be spayed before their first heat cycle, which typically occurs around 5 months of age.
  • Male cats — Male kittens should be neutered between 4 and 5 months of age.
  • Female small-breed dogs — Most female small-breed dogs whose projected adult body weight is under 45 pounds should be spayed prior to their first heat, which typically occurs around 5 to 6 months of age.
  • Male small-breed dogs — Most male small-breed dogs whose projected adult body weight is under 45 pounds should be neutered between 5 and 6 months of age.
  • Female large-breed dogs — Female large-breed dogs whose projected adult body weight is more than 45 pounds should be spayed between 5 and 24 months of age, depending on their disease risk and lifestyle.
  • Male large-breed dogs — Male large-breed dogs whose projected adult body weight is more than 45 pounds should be neutered after they stop growing, which is usually between 9 and 24 months of age, depending on the dog’s breed.

While spaying or neutering your pet is important to prevent unwanted litters and ensure your pet lives a long and healthy life, the best timing is critical. Contact our Neighborhood Veterinary Centers team, so we can help you decide when you should spay or neuter your pet to prevent problems and receive optimal benefits.