The findings highlight the importance of maintaining dogs at a healthy body weight throughout life, said the researchers.
"This is the first reported research of its kind looking specifically at a large number of pet dogs. The findings therefore provide important insights into the risks of being overweight for dogs in the general population", Salt said.
"Being overweight in middle age can have long-term consequences and, depending on breed, mean a reduction in life span of between one and ten months."
The findings were presented at a nutritional sciences symposium taking place from Tuesday in Portland city in the US state of Oregon.
