One of the rotten things about owning dogs is that they become like family and then they die (losing my Mastiff’s was almost as bad as losing my mother and they lived to 13, and 14 which is really old for a Mastiff mix). Could a dog breed be created that lived for thirty, forty, fifty or more years? Actually, this concept just made me wonder exactly what the physiological basis for accelerated canine aging (relative to humans) is anyway? Do their teliomeres shorten sooner (and ours sooner than certain specices such as sea turtles which out live us) or is there some other defined factor ? Has anyone ever tried caloric restriction with adequate nutrition to lengthen their dogs lives?
I don’t see why not (within limits). I would begin by breeding animals that worn born late in their parent’s lives. That should (over many generations) delay the onset of ‘old age.’
Well, they can do it with worms.
I’ve seen a commercial for dog food stating that a dog’s heartrate is the reason they “age” faster than humans. I have no idea if it’s true or not, but the claim is being made.
In general, it’s really hard to have selection pressure on conditions that only negatively affect a species in old age. So this would be tough, if it’s even possible.
The best way to do it might be to select for delayed maturation.
Humans have a much longer life span than other animals of our size. (And life span for mammals is roughly correlated with body size.) While no one knows exactly why this is, some speculate that it is because our development is substantially retarded relative to apes, and our sexual maturity is delayed. We essentially retain a juvenile form into adulthood.
Domestic dogs also retain juvenile characteristics relative to wolves. Interestingly, they also seem to be somewhat longer-lived than wolves. The maximum known age for a wolf in captivity seems to be 20, while the oldest dog lived to be 29. Smaller breeds (more juvenile-like?) breeds also tend to live longer than large breeds.
Assuming that, given perfect knowledge of the dog at birth, one could theoretically select out for longevity (and it’s not a more problematic limitation like for instance human’s lack of a third arm :)), you could breed dogs born at any time in their parents lifespan, if their parents are still alive and old, or lived into an advanced age. Sure, you don’t have as long a span in which to select, but assuming age is a theoretically-selectable trait I don’t see why it shouldn’t be almost as efficient as other characteristics.
I’m not a 100% on this but I’m pretty sure larger breeds live longer then smaller breeds. Rottweilers can live up to their mid-teens while Chihuahuas live up to a decade or so.
This study indicates that in general small breeds live longer than large breeds. This is not to say that some individual large breeds may live longer than some small breeds.
This site gives life spans for a variety of breeds. The largest breeds tend to have the shortest life spans (Irish Wolfhound 6.2 years, Great Dane 8.4, Rottweiler 9.8) although some larger breeds have longer spans. Small breeds tend to be pretty long-lived (Chihuahua 13.0 years).
All the sites I checked concur that small breeds on average tend to live longer.
Here’s one way you could select for longevity as a breeder:
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Start with a breeding population.
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Collect sperm from all males in the population.
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After the males die (or very late in their life span) artificially inseminate females with the sperm from the longest lived male animals.
It would be tougher with females. Perhaps, we could use certain biomarkers for aging such as the average circulating insulin levels and choose females who had the best profiles to impregnate with the “super” sperm.
I think everybody here is thinking in a too complicated a fashion.
Basically if accurate records are kept and there’s enough space and resources to breeed a few generations, it’s easy to select for longevity.
Say you have 20 dogs, call them generation A and the dogs a1, a2, … a20
You breed them randomly with each other, and produce generation B.
Then breed generation B randomly to produce C.
Now four or five generations down, you measure longevity of population A and start selectively breeding the descendants in generation D or E.
Now every selection step has to be made based on longevity of dogs 5-6 generations behind, so it will take longer, with possible false paths.
Doesn’t mean you have to freeze sperm or look for secondary signs.
- Groman
Your approach has the advantage of being able to select for longevity in both males and females however, it takes many (dog) generations to show results. My approach has the advantage of needing far fewer (really only one) generations to select in males. There is no reasons that the two approaches could not be combined. However, ultimately if someone wanted to do this I think the most efficient method would be to focus on biomarkers of aging. Researchers have discovered a number of different biomarkers which seem to correlate with the aging process and by choosing animals with eceptionally good markers in early or midlife to reproduce one could probably have good success.
IAA (former) Great Dane breeder/exhibitor, with 20 years’ experience. Danes have the latest maturity of any dog breed of which I am aware, with most females experiencing their first breeding season at 10 months or later (up to 18 months), as compared with most female dogs having their first at 5-6 months. The overwhelming majority of Danes are not fully physically mature until 3 to 4 years old (as opposed to most breeds at 12 to 18 months), and in environments which permit it, will show puppyish behaviors for at least the first two years. Despite these late maturity markers, Danes, as one of the “giant” breeds, are among those with the shortest average longevity. BTW, many Danes also show “primitive” wolf-like behaviors, even though the genetic analysis published last year doesn’t show them as having very wolf-like genes. 
Many of the reasons why Danes have low longevity are attributed to their size, and the metabolic and physiological stresses of all that rapid growth (although they mature slowly, most pups reach 90% of their adult height by 8-9 months old).
However, the most devastating mortality in all of the medium and larger breeds, or those defined as “deep-chested,” is related to “canine bloat” (Acute Gastric Dilatation) and torsion (volvulus), as it is for nearly all (including mutts) except the toy, terrier, and other relatively small breeds, which rarely ever get it. I heard of a chihuahua that bloated, some years back, but it’s really, really rare in small dogs.
I spent four years in the lab doing microbiological research related to AGD, and have never stopped thinking about it during the nearly 20 years since then. Someday maybe I’ll put all I’ve learned, and all my speculations, “out there” somewhere in hopes of getting something done. Goodness knows that nobody else’s research has gotten anywhere. 
As to size/longevity, I’m not persuaded there is some inherent limit (within reason). Horses grow every bit as fast as the “giant” breed dogs, and their lifespans are in the 20-30 year range, with some exceptional individuals living even longer. The fact that they’re herbivores is not relevant, as lions also grow very fast, and their lifespans (in captivity), while not as long as the horse’s, are certainly better than even “large” breed dogs, much less “giants.”
I am convinced that it could be done for the larger dogs, but it would be an enormous job, and would take some generations (guesstimate: 15 or more). When I was breeding dogs, I based my bloodline on a stud dog who lived to 12 years, and most of whose progeny lived to 10 or older (and he sired a lot of puppies). When I outcrossed, it was to another bloodline which also had some very long-lived individuals (although that bloodline was also very vulnerable to AGD). Those of my pups, from the first generation to the last, which were in “good homes” lived to 9 years or better, which is pretty phenomenal for Danes (but my stock didn’t do any better than any other good breeder working in the same bloodline). 
Had I been able to continue, I think I could have had my bloodline’s average longevity up at least a couple more years, but YNK. <sigh>
For the foreseeable future, however, if you want a dog that will live for 20 or more years, better get a toy, terrier, or other small dog. (One exception I’m aware of: Standard Poodles from highly competent breeders will surprise you sometimes with how long they live - so long as they don’t bloat or torsion.) And make sure you get it from an ethical breeder, who will honestly tell you all of the potential genetic flaws in both the breed and the individual bloodline. This is definitely one of those instances where a mutt is not preferable; you have no idea what genetic vulnerabilities it has, and no way of being sure that heterozygosity will cover them for you. Anyone who has ever watched Emergency Vet for very long has seen crossbreeds and mutts with some of the same health problems (and same enormous treatment costs) as the purebreds. Last and NOT least, take very good care of your dog, including spay/neuter (more important for longevity than most people know!), immunizations, heartworm meds, and other regular veterinary care.
Who says longevity would be a good thing? Think about the health care required by the oldest segment of human population. The oldest dog I’ve ever treated was a 25 year old toy poodle. The dog looked twice its age and was on a half dozen meds. I would much rather see dogs bred for improved health. There are dozens of diseases that we know the genetics of that are still common in canine populations. That would be a good place to start.
Amen. Great post tygerbryght. If you are ever in Pittsburgh I owe you a lunch:).
Would it increase lifespans to not breed females until they were toward the end of their fertile years?
You’d at least remove females with predispositions for young-adulthood fatal diseases.
Forget dogs. Let’s try breeding PEOPLE for longevity… Methuselah’s Children, anybody?
We’re already the Methuselahs, as mammals go at least. Any way you slice it, we live far longer than otherwise comparable species. As Asimov pointed out, for all mammals other than humans, the absolute maximum Guiness-record lifespan is somewhere in the vicinity of a billion heartbeats, plus or minus 30%… But humans reach our billionth heartbeat in our twenties, and can in the extreme live for four or five times that. And the average age of death of humans in developed countries is longer than the absolute maximum for any other mammal species. I would imagine that if we could determine exactly why we live so long already, it would be very valuable in determining how to extend lifespan further.
Perhaps genetic engineering can succeed where breeding does not.
Or diet?