Six out of 10 adult pet dogs are now overweight or obese, researchers at a Scottish university have found.
Risk factors which made dogs in the study more likely to be overweight included lack of exercise, being fed on table scraps, and being given too many snacks or treats .
Dogs were also more likely to be overweight if their owners were themselves obese or elderly, say the researchers.
'As in human beings, this had major health implications as obesity is known to predispose to or exacerbate a range of clinical conditions including arthritis, and ultimately decreased longevity,' say the researchers from Glasgow University.
'The proportion of the human population in the UK which is obese has increased by 400 percent in the last 25 years. With this increase of obesity in the UK, it is of relevance to veterinary surgeons that overweight people are more likely to have overweight dogs.'
Researchers took the measurements of 700 dogs aged one or over, and their owners, at five veterinary practices around Glasgow.
The results, published in the 'Journal of Small Animal Practice', showed that only 35 percent of the animals were classed as having the ideal body shape. In total, 59 percent were judged to be too heavy, including 20 percent that were clinically obese and 39 percent that were merely overweight. Only one in 20 dogs was underweight.
Further results showed that pets fed on table scraps were more likely to be classed as obese, while those that received snacks and treats were significantly more likely to be overweight.
Older owners were more likely to have overweight dogs and to give more snacks, with some dogs getting half a dozen snacks a day.
Owner income was also linked to risk, with pets of poorer people more likely to be overweight, the study reveals.