Dogs with Long Life Spans

It's not the norm for any breed to die at 3-5 years of age. Even very large breed dogs can usually make it to 9 or 10 if they're healthy. Most smaller to medium-sized breed regularly make 13. Many dogs pass that easily--even of the breeds you've mentioned, when properly bred and cared for. Some mixed breeds are healthier than some purebreds, but just because a dog is mixed does -not- indicate that it will necessarily be healthy--in fact, because health testing is rarely to never performed on mixed breeds unless illness is suspected later in life (they're typically not from planned breedings), and any health issues found in any of the parent breeds may be there genetically, it's often not even a smaller risk.

The surest way to get a healthy dog is to purchase a pup from a reputable breeder that performs the proper health tests, etc. These breeders can tell you what illnesses are common in the breed, and will test against those with tests available. You can have great luck even with shelter dogs, though, too. Most rescues should probably be able to give you at least some idea of the health of the dogs they adopt out. Buying a dog from a newspaper or similar source is a very risky thing, health-wise, as many of the dogs advertised there are bred purely for profit by people not particularly knowledgeable about the breed and its genetic risks.

Either way, keep them up to date on veterinary care, feed them a good diet, and keep them safe in a fenced yard or on leash and exercised sufficiently, and you should be on the right track to a healthy and long-lived dog.

The breeds with the fewest health concerns will tend to be those that have a good degree of genetic diversity without having been overbred or taken up by many puppy mills or so-called backyard breeders. Some physical traits also leave dogs more prone to certain health problems; a very long back with short legs can leave a dog prone to back problems, a very short muzzle and protruding eyes can predispose a dog to breathing problems and eye injuries.

Consider what traits you'd most like in a dog (aside from health and longevity, though those should also be taken into account), and from there it will be easier to figure out what breeds (and types of mixes) suit you and your lifestyle best. Then it's just a matter of either identifying a dog at a shelter that has those traits, or else contacting a reputable breeder or rescue of the breed you're interested in.

Typically the smaller breeds are longer lived. The more genetically diverse breeds are by far better.

Working breeds that have recent selective pressures for health and longevity are the best.

Being that so many of the large breeds have lifespans of as low as 6 years, to find working breeds with huge dogs living 10-15 years shows the importance of both environmental and human selective pressure to constantly make them stronger.

I raise Turkish Boz Shepherd, that live 10-15 years. But they are also a Livestock Guardian dog that is expected to travel 20-50 miles a day, find their own food, never provided shelter from the extremes of the weather, never vaccinated, never wormed and never pampered. The ones that can survive for 8-10 years are afforded the opportunity to pass on their genes.
So to have a 32-38 inch dog that weighes 140-200 pounds that can run 30+ miles an hour, and survive under those conditions to live 10+ years,,,, shows that we humans have failed to keep our dogs healthy by not selecting properly.

Note the muscling and lack of body fat of this 180 pound dog. True working breed.

But then again, I could not put my dogs through that either.

We love them.

I wouldn't go seek out a mixed breed assuming it would live longer. It's likely that you'd have other health issues anyway, if they're not being responsible breeders, and I wouldn't suggest supporting someone like that.

Within every breed there ARE breeders who do have longer lived dogs, it might take some looking but some of them are an option. My golden lived to 13 and still has some littermates alive now at 13 and a half. Her breeder takes longevity into consideration when breeding. But she also advocates for raw diet and minimal/no vaccines, which I think makes a difference too. 20 years ago there was a lot of heart issues in goldens and they started screening more for it so now it's not as big of a concern in the responsibly bred lines - I do hear of byb dogs dropping dead from heart issues here and there though.

Border collies have a pretty good lifespan, I would say around 14 is not unheard of.

But then there are breeds like dobes and bmd's that don't seem to be so lucky in the health department.