Puppy and kitten

When to Spay or Neuter? It’s Complicated.

February is Spay/Neuter Awareness Month, with World Spay Day to be observed on the fourth Tuesday. 

Like most veterinarians, we at Brownsburg Animal Clinic generally recommend spaying or neutering any pet not intended for breeding. 

But in recent years, we’ve been following research that indicates we should fine-tune each pet’s most appropriate age for the procedure, ranging from five months to as old as two years, depending on the pet. 

If you’re the owner of a kitten or puppy, our veterinarians will discuss the best time to spay or neuter your pet. 

The Benefits of Spay/Neuter

The practice of routinely spaying and neutering pets has long been recognized as the best way to reduce the pet overpopulation problem while saving pet owners the trouble and expense of unwanted litters.

Spaying helps protect female pets from serious health problems such as uterine infections and breast cancer. 

Neutering male pets can reduce the risk of developing an enlarged prostate and testicular cancer.

Many owners find their pets’ behavior improved after surgery to remove their ovaries or testes. While the procedures have no effect on a pet’s intelligence, activities or performance, spaying and neutering can reduce unwanted behaviors associated with mating instincts, such as roaming, aggression and marking. 

Many people believe spaying and neutering makes pets better companions.

When to Spay or Neuter? These Days, It’s Complicated.

During the past decade, veterinary researchers have come to understand the hormones that make procreation possible and cause undesirable mating behaviors may also affect pets’ overall health. For dogs, it now appears the most appropriate age for spaying and neutering can vary widely from pet to pet. 

While the consensus among feline specialists is to spay or neuter all kittens not meant for breeding before five months of age, evidence is accumulating to suggest routinely spaying or neutering all dogs at the same young age may increase the risk of orthopedic problems and some types of cancer for some animals. 

One 2020 study of 35 dog breeds suggested early sterilization in some dogs appeared to increase the risk of diseases such as cranial cruciate ligament rupture, hemangiosarcoma, mast cell tumors, lymphosarcoma and hip dysplasia. 

According to the study report, “The overall major finding from the present study is that there are breed differences—and sometimes sex differences—with regard to the increased risks of joint disorders and cancers associated with neutering at various ages.”

The study’s authors encourage using data-based information to make case-by-case decisions with your veterinarian about the appropriate age to neuter your puppy or young dog. 

The authors noted, “an elevated risk for a joint disorder or cancer occurs in relatively few of these breeds. In other words, with most breeds or sexes, neutering can apparently be done without referral to a particular age, at least with regard to the joint disorders or cancers covered in this study.

“To just delay neutering by a year or so to lower the risk of a joint disorder or cancer in those breeds where the issue is relevant, is a noteworthy goal, making it worthwhile [for veterinarians] to discuss appropriate ages to neuter with caregivers who have a new puppy.”

Our Advice

At Brownsburg Animal Clinic, we strongly recommend spaying and neutering at the appropriate age as the best option for any dog or cat not intended for breeding. 

For kittens, we agree with our colleagues specializing in feline medicine that the procedure should be done before five months of age.

As we learn more about the long-term risks of routinely spaying and neutering dogs at a set young age, we are taking a more individualized approach to recommending the ideal age for the surgery based on your pet’s breed, size and gender. We’ll talk with you about what the latest research indicates is the best time to spay or neuter your pet. 

Additional Reading

The American Veterinary Medical Association offers general background information for pet owners on spaying and neutering.  

The AVMA website also has a page about spaying and neutering for veterinarians, offering guidance on making the best recommendations for their feline and canine patients.

The American Animal Hospital Association’s article, “When should I spay or neuter my pet?” outlines the considerations to discuss with your veterinarian when deciding the appropriate age for spaying or neutering.

Frontiers, a publisher of scientific research papers, offers the full text of the 2020 study report referenced above.

The 35 breeds included in the study are, alphabetically, Australian Cattle Dog, Australian Shepherd, Beagle, Bernese Mountain Dog, Border Collie, Boston Terrier, Boxer, Bulldog, Cavalier King Charles Spaniel, Chihuahua, Cocker Spaniel, Collie, Corgi (Pembroke and Cardigan combined), Dachshund, Doberman Pinscher, English Springer Spaniel, German Shepherd Dog, Golden Retriever, Great Dane, Irish Wolfhound, Jack Russell Terrier, Labrador Retriever, Maltese, Miniature Schnauzer, Pomeranian, Poodle-Miniature, Poodle-Standard, Poodle-Toy, Pug, Rottweiler, Saint Bernard, Shetland Sheepdog, Shih Tzu, West Highland White Terrier, and Yorkshire Terrier. 

In addition to general guidelines related to body size, the report includes specific recommendations for each breed.