Thats a bit random!!! My petite basset has leftovers every night and a sausage or sausage roll every lunchtime and is a healthy 15 year old. its more an exercise issue. My dog comes to work with me so can run round to his hearts content.
That is what happens to dogs that don't get excise and are forced to live in the house all day and only go out to potty. Bored dogs with lazy owners get fat. OR it could be a medical condition.