When to Spay or Neuter Your Dog
The veterinary profession continues to learn about the long-term health effects of surgeries done to prevent unwanted canine pregnancies. These insights help Dog Moms and Dads make better decisions about when to spay or neuter dogs. Simply put, our goals must bridge both reproductive protection and long-term comfort and health for the dogs we love. Researchers from UC-Davis looked at associated joint disorders, cancers, and urinary incontinence in 35 dog breeds and offered insights on making this important decision. In some cases, the best option may be leaving some dogs intact.
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IMPORTANT LINKS TO THE PRIMARY SOURCES
Full journal article from Frontiers in Veterinary Science
Supplementary materials with details on orthopedic and cancer risks by breed
Breed Differences: When to Spay or Neuter?
The answer to the big question is that it really depends on the dog, so NO single answer fits all breeds or ages. Also note that they refer to both surgeries as "neutering," so don't let that confuse you. They're talking about altering both female and male dogs when using that word.
Researchers found "major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers."
They also go on to explain their goals as follows: "The primary purpose was to offer readers some evidence-based information on breed-specific differences with vulnerability to neutering, including suggested guidelines for neutering ages to avoid increasing long-term health risks of neutering, if any. A secondary, unforeseen, purpose was to document breed-specific differences in the increases in some cancers associated with removal of gonadal hormones, as an area for possible research on genetic aspects of cancer occurrence."
Suggested Guidelines by Breed and Sex
The article includes a chart that shows several categories for suggested guidelines for when to spay or neuter dogs of different breeds, divided by sex. Their guidelines include these options:
- Leave intact
- Choice (which simply means "there was no increase risk [of joint disorders or cancers] for any age" of the breed / sex noted)
- Beyond 6 months
- Beyond 11 months
- Beyond 23 months
For more of the 35 breeds considered, only 2 ended up listed as Leave Intact:
- Male doberman pinscher
- Female golden retriever
Most of the breeds fell into the Choice category. Other breeds got classified with some benefit of waiting to spay or neuter dogs until they are over certain ages:
- 6 months
- 11 months
- 23 months
The recommendation to wait includes the breed most important to my current life -- border collies. Study authors from UC-Davis explain, "The suggested guideline for neutering, given the significant risk of cancers, is holding off neutering both sexes until beyond a year of age."
I'm happy to say that we did with both Clover and Tori. In hopes of solving Clover's non-stop UTIs as a puppy, we specifically allowed her to go through one heat cycle. Then, she was a LATE bloomer and went through a long false pregnancy, so she was about 17 months old when she was spayed. For Tori, we waited as long as we could for general health reasons. She literally went into her first heat right before her scheduled surgery -- around the 11 month mark (assuming we've guessed correctly at her likely birthdate).
When to Spay or Neuter Your Dog -- See for Yourself
Here's the full list of breeds from the research so that you can see if yours was included. If not, maybe look at the most likely breeds in your mix or that are most like your dog and see what it says. Essentially, they chose the breeds that occur most frequently in the veterinary teaching hospital database + others needed to offer a sampling of both giant breeds and small breeds:
- 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
- Yorkshire Terrier
Find More More Details in the Supplemental Materials
In addition to the short sections in the main article for each breed, you can also access more detailed supplementary materials for each breed, which provides additional info such as:
Associated risks for joint disorders based on age of neutering:
- Hip dysplasia
- Cranial cruciate ligament rupture
- Elbow dysplasia
Associated risks for each of these cancers or "at least one" of these cancers based on age of neutering:
- Lymphoma
- Mast cell tumor
- Hemangiosarcoma
- Osteosarcoma
Trending Which Way
I know top-level dog people who do not neuter their male dogs ever, feeling there is no medical benefit to doing so.
Many top dog pals who have female dogs allow them to go through at least one heat cycle, feeling that it's better for their long-term health, even though doing so slightly increases the risk of mammary cancer in female dogs (about 8%, according to our internal med specialist).
I'm sure there are people as well who never spay female dogs, but to me the risks are too great not to:
- Unwanted pregnancies and puppies
- Risk of mammary cancer, which is deadly
- Risk of life-threatening uterine infection called pyometra
If you adopt your dog from a shelter or rescue group, you may NOT have a say in when to spay or neuter your dog. Their responsibilities and goals, even from a veterinary medical perspective, remain different from those of individual families.
I don't see that widely changing anytime soon ... though I'm incredibly thankful the rescue group from which we adopted Clover did not spay her at 15 weeks old and allowed me to make the best medical decision for her.
My Past Mistakes
Alas, I did not know better at the time in 2000, and I had our old boy Ginko neutered when he was like 6 months old. I believe to this day that's the reason he blew both knees -- cranial cruciate ligament rupture -- at the age of 3.
Quick other note ... We're seriously considering adding much more frequent video content to our YouTube Channel. We are galaxies away from hitting the stats required to make any advertising revenue over there, but if you could subscribe to our channel, it will help move us the right direction.
See the video version of this same information below.
