Obesity is an accumulation of excess body fat. Extra body weight and extra body fat tend to go hand in hand, so most overweight dogs will have excess body fat.
Obesity shortens a dog’s life and makes them more likely to develop disease. It was always accepted that heavy dogs lived a shorter lifespan than lean dogs, usually by 6-12 months. But a large, lifetime study of Labrador Retrievers has found that being even moderately overweight can reduce a dog’s life expectancy by nearly two years compared to their leaner counterparts.