By Jonathan Amos BBC News Online science staff

The survey, published in the Veterinary Record, asked more than 3,000 owners to provide information about their animal's breed, lifespan and cause of death.

The survey has thrown up interesting new information about pet longevity and the diseases affecting the nation's domestic animals. It also underlines the fact that different breeds have very different lifespans.

LIFE EXPECTANCY - YRS

Collie - 13.0 Labrador - 12.6 German shepherd - 10.3 Rottweiler - 9.8 Great Dane - 8.4 Bulldog - 6.7

Professor Bob Michell, who is President of the Royal College of Veterinary Surgeons and author of the Veterinary Record article, said the survey was probably the first to build up a clear picture of dog longevity.

He said it would provide absolutely vital, baseline scientific information - as well as giving owners a better idea of how long their pets were likely to be with them.

The results show the mean age at death - for all breeds and all causes of death - is 11 years, one month. The age is slightly higher in dogs dying of old age at 12 years, eight months.

According to the study, only 8% of dogs lived beyond 15, and 64% died of disease or were put to sleep because of their illness. Mongrels lived longer than most pedigree dogs, but a few pure breeds did outlive the mongrels. These included Jack Russells (13.6 yrs), whippets (14.3) and miniature poodles (14.8).

Genome projects

Nearly 16% of deaths were attributed to cancer, twice as many as to heart disease. The survey also found that neutered females lived longer than males or intact females.

"For those who are interested in the biological causes of longevity - which hugely affects us, of course, as human beings - what better species to study than the dog when we know there are considerable differences in longevity between breeds that are remarkably similar," said Professor Michell.

Jack Russells are long-lived dogs

This is one of the driving forces behind the Dog Genome Project which, like the Human Genome Project, aims to unravel the hereditary instructions that make each individual unique.

The benefits of comparative genomics will go both ways. Dogs and humans share genes for a number of illnesses - blindness, epilepsy, and some cancers - and any new therapies are likely to work for both.

Professor Michell says we should forget the idea that six years of human life equates to one year of dog life. "It's a nonsense. Like many other things about dogs, longevity depends on the breed."