Size vs breed

[sonofapun]

What has more of an impact on life expectancy - the dog's breed or its size?

I have a cross breed, and all the breeds that make him up (retriever, poodle, couple of others) all have a lifespan of 12-15 years.

However, he's very large. Almost double the average weight, putting him more on a par with those very large breeds who tend to live only 9-10 years.

I know it's all a matter of genetics and luck at the end of the day, I'm just not sure what category he falls into.

Anyone?

Average weight of what? How big is he?

We had a 35kg dog who lived to 13, but we kept him slim and very fit - that also plays a part.

It's more breed dependent. Size can be a factor; small dogs tend to live longer than the very large, but certain breeds can have a longer lifespan than other breeds of equivalent size.

I have a giant breed - Pyrenean Mountain Dog, which is slightly larger than a Bernese Mountain Dog but has a longer life span. Bernese average 7-10 years but two of my girls have lived to 12.5 years and another to 11.5, which would be very unusual in Bernese and some of the other giant breeds. Anatolian Shepherd Dogs can live into their teens but are also bigger than others with an expected lifespan of 8-10. Some large spitz breeds also tend to be long-lived.

At a guess I'd say 10-12 for your large male, given that bitches tend to live a year or two longer than dogs.

My breed's (Border Terrier) life expectancy is around 15. She is the same size as a French Bulldog whose life expectancy is around 5 on average.

My friend has a Newfoundland. All his relatives made 15+

It's a combination of things.

Sorry, just to clarify - I think the average weight for a lab/standard poodle cross is 20 - 30kg, and ours is 45kg, everyone always comments on how large he is.

Sounds like it's more his breed than size that will dictate things though?

Although I do realise it's a 'how long is a piece of string' question

It’s hard to know tbh - it’s a nature v. Nurture type question. I often think the same for one of my dogs - he’s about 15KG bigger than breed average and far taller as well. TBH I try not to dwell as it’s so depressing to think about the fact I might lose him early because he’s large for his breed

I had two large oversized labs, they were 40kg and 42kg, not overweight. One lived until 10 when we had him eurhanised for cancer and the other was 12 almost 13 when we let him go as his legs were getting weak. He also had epilepsy and was medicated, so he lasted longer than we expected really.
I think that the advice to just enjoy them is sensible, anything can happen at any time with any dog.

Genetics has a big part to play. If they predispose to cancer, and the dog is inbred and gets a double dose, it's likelier to die younger than a dog born of an outcross to either a healthier line or a breed that doesn't have the same issues.

@Newpeep wow I didn't know that about French Bulldogs, I thought it would be a bit higher than 5! That is sad.

We had a Tibetan terrier/cavalier mix (we got her off a random Facebook post, from a woman whose daughter we are almost certain bought her at a puppy mill) and she was fairly small but just never really healthy. She had breathing issues almost all the time we had her, and the vets could never figure it out except to say they didn’t think it was fatal.

She had just turned 7 when she died. It was my birthday a few years back when she curled up on the couch to nap in her favorite spot and just never woke up, my poor baby.

This time around we got a beagle. We wanted a smaller breed with fewer health issues, and so far he doesn’t have any.

Had three Great Danes, last were rescues. My first made nine and a half as did the second, who was very big. The last one was dumped, DH, (vet,) thought she was about two and we were really lucky to have her for over nine years.

Wow! That's so good to hear. You clearly care for your dogs very well.

I guess I'm less interested in a people's personal experience of big/small dogs and their age at death, because there'll naturally be all sorts and anecdotes don't tell us much.

The data I'm trying to get to, and I feel must exist somewhere, is whether the average lifespan for a breed only applies to dogs of an average size for the breed, and if they're substantially larger, if the lifespan is reduced accordingly, from looking at the stats. But I can't find any stats.

I don't know of any official data but I can think of 2 dogs that I have known personally, that were very large examples of their breeds and neither did well in later life.
My best advice would be to keep your dog at his healthiest minimum weight, super lean to minimize stress on the joints and also the heart.
In my experience dogs that are kept on the lean side are less likely to suffer from mobility issues, and if your dog was to get arthritis it would still be advantageous to be slimmer.
Genetically with a mixed breed it's very much luck of the draw. Very few mixed breeds come from health tested parents and it's really a case of wait and see.

Hopefully you'll have many happy years with your dog. None of them live long enough though.

The life expectancy for a French bulldog is 10 to 12 years

Working bred labs maybe 20-30kg but show bred labs tend to be much stockier build and more 30kg+ so don't think 45kg is that out there for a lab male if yours takes more after those genes.
I assume the basic data from vet records maybe used for science and insurance companies to work out risk factors for each breeds.

Its not worth worrying about when you already have the dog rather than when selecting a new breed as it will only be an estimate. I've lost some dogs too young and one I kept as people were put off adopting a senior (7) but lived another decade. Luckily for her I'd invested in decent pet insurance and always focused more on how she behaved than her age because if I'd assumed she'd probably die at 12-13 as a large dog and opted to avoid anesthetics/specialist vets treatments as some owners suggest they'd do she'd likely have declined and required euthanising earlier.

The only thing you really have some control over is the food, weight and exercise. Much like us keeping lean and fit reduces the strain on joints/ligaments and risks of developing many diseases.

Sadly, not anymore. They're so overbred that the average lifespan in the UK is now 4.5 years of age.

www.newscientist.com/article/2318084-french-bulldogs-are-the-shortest-lived-dog-breed-in-the-uk/

That’s 4-5 years of misery, pain and suffering as well 😣

It's horrendous isn't it? @Killingoffmyflowersonebyone

It's also such a shame as all the Frenchies I know have great temperaments and are great with children, but their health issues just mean it would be so irresponsible to buy one.

I believe they're now banned in some countries too.

I've not had a large breed that's lived beyond 10 but it does depend on the breed. I have two Mastiff crosses who are 50kg each and don't count on a long life expectancy.

I don’t think there’s that much point dwelling on what ifs. I have giants, some of which do make double figures. Ive also had quite a few GSD make 13-14 which is old for a large breed dog (30-50kgs) Saying that some don’t get past 5, just because a breed can live a long life doesn’t ensure it will. I’ve lost a fair few prematurely, mostly diseases typical of the breed they were.

My mixed breed was the unhealthiest dog I have ever had though. Plagued with health issues from both of his crosses.

I've had a jack russle that lived for 19 years and a Neighbor who owned an Irish Wolf found that lived to only 4 years
I think smaller dogs lives longer

IIRC, insurance costs for cross-breeds are lower than for pedigrees, which tells you a lot (I say this as the owner of two pedigree dogs).

Anyway, some links:
https://link.springer.com/article/10.1007/s10592-019-01240-x (abstract)
Small dogs live longer; mixed breed dogs live longer after controlling for size; inbreeding reduces life expectancy.

https://link.springer.com/article/10.1007/s11357-022-00653-w (abstract)
Small dogs live longer; inbreeding reduces life expectancy.

https://www.nature.com/articles/s41598-023-50458-w (whole article
Quite a technical article, drilled into the differences between breeds (breeds within a clade will have lifespans more similar than chance would suggest; head shape has an impact on life expectancy, small breeds live longer, and so on).

That should get you started.

That third one is very interesting reading, @EdithStourton . Thank you.

No problem.
Google Scholar is your friend for things like this.