Why Cancer Is Common In Some Dog Breeds

Updated January 30, 2021

I saw a beautiful, not old dog recently, and before I even touched him I knew what was wrong.

He was a Bernese Mountain Dog with enlarged lymph nodes, and I knew he had cancer in the same way I know it when:

  • a Rottweiler limps in a certain way
  • a German Shepherd suddenly goes pale and weak, or
  • a Staffie gets a lump on the leg

I hate this. I really hate the inevitability of it all. Because the fact that vets can draw links between breeds and cancers is anything but random.

It goes to the heart of why dogs get so much cancer.

The Number 1 Cause Of Cancer In Dogs

It’s staring us right in the face. It’s their genes.

Not pesticides, or whether they’re desexed, or processed foods. Yes, we know that cancers can have other risk factors, but these all seem insignificant when compared with the genetic ones.

Any time a disease is more common in one dog breed than another, part of the reason has to be in their DNA. Yet like so many genetic diseases of dogs, we take it for granted that it has to be that way. It doesn’t.

Why Cancer Is Common In Certain Dogs

The cancers we’re talking about have their origin in a genetic mutation, which was probably present from birth. There are plenty of human equivalents, but they aren’t the same. In a human population, each faulty gene is generally uncommon, and each carrier probably only has one copy.

Compared to humans, purebred dogs are all inbred.

Once upon a time dogs were just dogs in all their shapes and sizes. Then around 200 years ago, each of the breeds was defined and isolated, often from a small number of founders.

To be a purebred dog, you need to show that you’re only descended from these dogs. To make matters worse, we have:

  • frequent use of popular sires
  • inbreeding practices 
  • population bottlenecks (such as in WWII)

All of which further reduce genetic diversity. Meaning that in certain breeds, mutations that were formerly rare become common, and some individuals even end up with two copies.

The Dog Breeds Prone To Cancer

The rate of cancer in dogs is not evenly spread. There are some breeds that hardly get cancer until they’re old, and others for whom it’s far too common. I want to share with you three big studies with dog cancer statistics.

In each case the number refers to the percent of dogs of that breed who died of cancer. In each case I only show the dogs with above average risk.

First, this study of insured Swedish dogs.

Breed% Cancer-related death
Bernese Mountain Dog41
Golden Retriever30
Irish Wolfhound22
Labrador Retriever21
Springer Spaniel21
Pyrenees (Pyrenean)20
St Bernard19
The average for all breeds was 18%

Second, this study from the USA containing more breeds.

Breed% Cancer-related death
Bernese Mountain Dog55
Golden Retriever50
Scottish Terrier48
Bouvier des Flandres47
Irish Setter41
Airedale Terrier40
Gordon Setter38
Basset Hound38
Norwegian Elkhound37
Rhodesian Ridgeback37
Pyrenees (Pyrenean)36
Old English Sheepdog36
English Setter36
Afghan Hound35
Alaskan Malamute34
Labrador Retriever34
English Pointer34
Cairn Terrier32
Irish Wolfhound32
Boston Terrier30
Pembroke Welsh Corgi30
Shetland Sheepdog30
English Springer Spaniel30
Siberian Husky29
Chesapeake Bay Retriever29
German Shepherd Dog28
Mixed-Breed Dogs had a rate of 0.276%

And lastly, this UK study that contains one extra statistic.

Breed% Cancer-related deathMedian age at death
Irish water spaniel569.3
Flat-coated retriever509.8
Hungarian wirehaired vizsla479.8
Bernese mountain dog468.0
Italian spinone459.0
Staffordshire bull terrier4412.7
Welsh terrier4312.7
Giant schnauzer4110.0
Airedale terrier4010.7
Golden retriever3912.2
French bulldog389.0
Alaskan Malamute3610.7
Saluki/gazelle hound3612.0
Nova Scotia duck tolling retriever338.0
Basset griffon vendeen32.912.0
English setter32.811.6
Norwegian elkhound32.413.3
Siberian Husky31.812.6
Tibetan terrier31.612.2
Basset hound31.011.3
Labrador retriever31.212.2
Afghan hound30.811.9
Rhodesian ridgeback30.611.0
Irish red and white setter30.211.4
Standard poodle29.712.0
German shorthaired pointer29.612.0
Cocker spaniel/English cocker29.411.2
Field spaniel29.411.6
Welsh corgi Pembroke28.412.2
Welsh corgi cardigan28.312.2
Gordon setter29.311.1
Irish setter27.312.0
Average mortality rate to cancer for all breeds was 27% 

You can see that certain breeds reappear in each study, and others only appear once. These might be breeds only popular in one place, or breeds where the risk varies between countries. Or it might just be chance.

The UK study adds an important point: it matters much more if a dog dies of cancer at 8 than if they died of it at 13.

Are Cancer Rates In Dogs Increasing?

There are several reasons why it might seem that cancer in dogs is getting more common.

  1. Cancer rates are actually increasing
  2. Dogs are living longer lives, and so cancer will be a greater cause of death
  3. Dogs receive better veterinary care, and therefore more accurate diagnosis

I think the true reason is a mix of all three. I believe that the giant breeds are getting more cancer due to their increased size. I also think that it’s hard to deny the loss of genetic diversity with each generation.

But I also have seen the advances in both how pet owners look after their dogs, and how vets can treat them. For that reason, I’m not too alarmed. But I would dearly like to see more breeders of high-risk breeds making an effort to select for dogs less likely to die early of cancer.

Yes it will be hard. It would mean either choosing family lines that have had fewer cancers in the past, or identifying the faulty genes and testing before breeding.

The statistics tell us it’s possible.

Related: Lifespans Of Dog Breeds | How To Help Your Dog Live Longer


Bonnett, B. N., Egenvall, A., Hedhammar, Å., & Olson, P. (2005). Mortality in over 350,000 insured Swedish dogs from 1995–2000: I. Breed-, gender-, age-and cause-specific rates. Acta Veterinaria Scandinavica, 46(3), 105

Fleming, J. M., Creevy, K. E., & Promislow, D. E. L. (2011). Mortality in North American dogs from 1984 to 2004: an investigation into age‐, size‐, and breed‐related causes of death. Journal of Veterinary Internal Medicine, 25(2), 187-198

Adams, V. J., Evans, K. M., Sampson, J., & Wood, J. L. N. (2010). Methods and mortality results of a health survey of purebred dogs in the UK. Journal of Small Animal Practice, 51(10), 512-524

Have something to add? Comments (if open) will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here.

4 Replies to “Why Cancer Is Common In Some Dog Breeds”

  1. Our black labrador sadly passed away from cancer (Disseminated Histiocytic Sarcoma) in October and he was only 5 years old. 🙁

  2. Thank you so much for rounding up all of this information and publishing it here so those of us on the US Gulf Coast can find it. I love how you include all important details and references.
    I wish you well and thank you, Lundy in Gulf Shores, Alabama

  3. Hi Andrew,

    I just want to say thank you for your regular articles that are full of information with supporting stats and pics.

    I read most of them in details, dogs related, and I thoroughly enjoy them. I appreciate your effort writing them, very informative and easy to read.


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