New York: Large dog breeds like the great danes apparently die younger because they age faster than small pups, like chihuahuas, a new study has claimed.
In dogs, large breeds often die young compared with smaller ones, with a 70kg Great Dane having an average life span of about 7 years, while a 4kg toy poodle can expect to live up to 14 years.
To shed light on the possible tradeoffs of large size, German researchers analysed ages at death in 74 breeds, using data from more than 56,000 dogs that visited veterinary teaching hospitals, LiveScience reported.
The researchers focused on why large dogs lived shorter lives on average.
"My main scientific interest is life-history evolution. I`m also a bit of a dog nerd in private life," said researcher Cornelia Kraus, an evolutionary biologist at the University of Gottingen in Germany.
The scientists found that large breeds apparently aged at faster rates; the speed at which the risk of death increased with age was greater with larger breeds than smaller ones.
Among dog breeds, an increase of 2 kg in body mass leads to a loss of approximately 1 month of life expectancy.
The researchers plan to follow the growth and health histories of a large number of dogs and pinpoint the leading causes of death for large dogs.
For instance, bigger canines apparently suffer from cancer more often, which could make sense; large dogs grow more than smaller breeds do, and cancer is rooted in abnormal cell growth.
"This research should be feasible in dogs, since I found that dog people in general seem very open, and interested to contribute to research on their favourite species," Kraus told the website.
The study was published in the journal American Naturalist.