When to Spay or Neuter a Bernese Mountain Dog

By the Riverside Berner Guide editorial team
Last updated November 7, 2026

There is no single agreed answer to when to neuter a Bernese Mountain Dog. The one study with numbers for Berners linked neutering males before age 2 with more joint disorders and found no significant increase in females, while veterinary guidelines for large dogs in general set a different timeline for males. Timing is a medical decision, so ask your vet.

This page sets out what the evidence says, where it falls short, and what the breed club and puppy contracts expect. It doesn’t recommend an age. Use it to get ready for that talk with your vet.

Why the timing question matters

Spaying and neutering have real benefits. The AKC lists preventing pyometra, a serious infection of the uterus, along with removing the risk of testicular cancer and lowering the risk of breast cancer in females. The 2019 AAHA guidelines recommend spaying or neutering every dog not meant for breeding, and say sterilized dogs of both sexes live longer on average than intact dogs.

The harder question is when. Spaying or neutering removes hormones that a puppy has while it grows. The AKC’s list of possible risks includes a greater chance of some cancers, more orthopedic problems and urinary issues.

The researchers behind the main study proposed one reason for a joint link. If a dog is neutered well before its growth plates close, the long bones may grow a little longer than normal, which could upset joint alignment in some dogs. That is a proposed explanation, not a proven cause.

Why big breeds get extra attention

Berners are a big breed. The BMDCA’s FAQ says adult males generally weigh 80 to 115 pounds and females 70 to 95 pounds. Its buying tips add that the breed is well known for serious orthopedic problems such as hip and elbow dysplasia.

That is why owners neutering large breed dogs hear more about timing than owners of small dogs. For background on those joint problems, see hip and elbow dysplasia in Bernese Mountain Dogs.

What the research says about when to neuter a Bernese Mountain Dog

The 2020 study of 35 breeds

The study most people cite was published in Frontiers in Veterinary Science in 2020 by a team at the University of California, Davis. The team looked back through the records of the university’s veterinary teaching hospital, covering 15 years of data for most breeds. They compared intact dogs with dogs neutered at under 6 months, 6 to 11 months, 1 year, or 2 to 8 years.

They tracked three joint disorders: hip dysplasia, cranial cruciate ligament tears or ruptures, and elbow dysplasia. They also tracked four cancers: lymphoma, hemangiosarcoma, mast cell tumors and osteosarcoma. In females, they looked at mammary cancer, pyometra and urinary incontinence too.

The Bernese group had 235 dogs in all: 59 intact males, 74 neutered males, 37 intact females and 65 spayed females.

What it found in male Berners

Among intact males, 4% had at least one of the joint disorders. In males neutered at any age before 2 years, the figure was 23 to 24%, about six times higher. This difference was statistically significant.

The tracked cancers showed up in 9% of intact males. The study found no clear rise in those cancers among neutered males.

What it found in female Berners

Among intact females, 11% had at least one joint disorder. Females spayed before 6 months had more than three times that rate, but the difference wasn’t statistically significant.

The tracked cancers showed up in 9% of intact females, and females spayed before 6 months had about twice that rate. The authors didn’t find a significant increase in either joint disorders or cancers in spayed females. No mammary cancer or urinary incontinence was recorded in the Bernese females, and 5% of intact females had pyometra.

The authors’ suggested guideline

The paper ends each breed’s summary with a suggested guideline. For Bernese males, the authors suggested delaying neutering until well beyond 2 years because of the joint findings. For females, since no significant increase was found, they left the age to the owner’s choice.

Treat this as one research team’s reading of one hospital’s records. Other experts weigh the same trade-offs differently, as you’ll see below.

A Swiss study of Bernese lifespan

A 2016 study followed 389 Berners born in Switzerland in 2001 and 2002 and registered with the Swiss breed club, using questionnaires filled in by owners and vets. Females lived longer than males. The study looked at neuter status too, but many dogs with unknown status were left out of that analysis, and the age at neutering wasn’t taken into account.

The authors concluded that any effect of sex hormones on survival was unclear. Read more in our guide to Bernese Mountain Dog lifespan.

Limits of the evidence

These studies are useful, but they can’t predict what will happen to your dog. Keep these limits in mind when you read the numbers.

• How the study was done. The 2020 study looked back at existing hospital records rather than following dogs forward. Dogs whose neuter age couldn’t be found were left out, and the records didn’t say why owners chose to neuter or not.
• One hospital. Every dog came from the same veterinary teaching hospital in California.
• Small groups. 235 Berners were split by sex and again by neuter age, so some groups were small. The authors note that when a disease is rare in a group, a real difference can be missed.
• Short follow-up. Dogs were tracked until their last hospital visit, or through age 11. Across all 35 breeds, the average last record came at about 4.7 to 5.7 years of age, so problems that show up later may be undercounted.
• What “risk” means. Each figure is the share of dogs in a group that were diagnosed while they appeared in the records. “Six times higher” is a relative number; the absolute numbers were 4% and 23 to 24%. Both matter.
• Links, not causes. AAHA notes that much of the spay-neuter research shows an association, not cause and effect.
• Cancers left out. The study didn’t track histiocytic sarcoma. The BMDCA says Berners are one of the breeds more commonly affected by it, so see cancer in Bernese Mountain Dogs too.

What professional guidelines say

The AAHA guidelines

The 2019 AAHA Canine Life Stage Guidelines cover all dogs, not Berners alone, and AAHA describes them as a guideline rather than a standard of care. They define large breeds as dogs expected to weigh 45 pounds or more as adults, which takes in Berners at the BMDCA’s typical weights.

For large-breed males, AAHA suggests waiting until growth is complete, usually between 9 and 15 months, and says there may be an orthopedic benefit to waiting longer. On when to spay a large breed dog, it gives a range of 5 to 15 months but says the answer is less clear. It calls for clinical discretion and a full discussion with the owner.

AAHA also says the evidence on joint disease and timing isn’t strong enough for firm conclusions. It notes that findings from one breed may not apply to all breeds, and that better data are needed for particular sizes and breeds.

Weighing other conditions

AAHA says spaying before the first heat minimizes mammary cancer risk, and that the risk rises with the number of heat cycles up to 2.5 years of age. The 2020 study’s authors point to a review that found the evidence linking spaying to lower mammary cancer risk is weak.

AAHA adds that urinary incontinence is more common in spayed females overall. It also says most, but not all, studies find a higher risk of obesity after spaying or neutering.

AAHA’s suggestion for large-breed males and the 2020 study’s guideline for Bernese males don’t match. That gap is one more reason to talk it through with your vet.

The AKC’s view

The AKC says there’s no one-size-fits-all answer. It advises reaching the decision, and the timing, through an informed discussion with a vet about the risks and benefits.

The same article notes that some surgeries prevent breeding while leaving the hormone-producing glands in place. Whether any of these suits your dog is a question to ask your vet.

The BMDCA’s position

The club’s code of conduct encourages members to place any dog not suited for breeding with AKC limited registration and a non-breeding contract. That contract should recommend spay/neuter at an age consistent with recent studies. The code doesn’t name an age.

The BMDCA’s buying tips say a conscientious breeder uses spay/neuter agreements, limited registration or both for pet puppies. They also flag any breeder who requires you to keep a male intact so the breeder can use him for breeding.

What puppy contracts commonly require

Most contracts for pet puppies include a spay/neuter clause. The AKC says most breeder contracts require it for pet-quality dogs, but the required age varies a lot. Some breeders ask owners to wait until the growth plates close, which assumes you can keep the dog securely contained.

Pet puppies are usually sold on limited registration, according to the AKC. A dog on limited registration can take part in all AKC events except conformation, but none of its puppies can be registered.

The BMDCA’s guide to responsible breeding says a contract should spell out terms such as the spay/neuter agreement and the timeframes for meeting them. The AKC suggests checking with your vet in advance and making sure your vet is on board with the contract’s timetable.

If the contract’s date and your vet’s advice don’t match, raise it with the breeder before you pay anything. For more on the fine print, read deposits, contracts and waitlists explained and how to find a reputable Bernese breeder.

Questions to bring to your vet

You don’t need to decide at the first puppy visit. Bring this page along, and use these questions to start the talk:

• How do the 2020 study’s Bernese findings apply to my dog’s sex?
• How is my puppy growing, and what do the parents’ hip and elbow results tell us?
• Is there cancer in my puppy’s family history, and does that change anything?
• What are the risks of waiting, such as heat cycles, pyometra or an accidental litter, and can we manage them at home?
• Are there surgeries that keep the hormone-producing glands, and would one suit my dog?
• Does the deadline in my puppy contract fit your advice?

Your vet knows your dog, and the decision belongs to the two of you. For the wider picture, our main guide to Bernese Mountain Dog health problems covers the conditions the breed faces most.