I found a good article relating to this topic of overweight dogs...

"People overfeed their pets for a number of reasons. It’s easier to put the food down and leave it than to schedule meals and monitor the amount. Even the fattest pet can give a convincing, heart-rending portrayal of a victim of starvation."

Pets and Pounds: http://www.vetcentric.com/magazine/m...ARTICLEID=1730