Thanks for the information.
Since they've gotten the trainer, they have stopped feeding the dogs table scraps. I'm not sure how long the dogs have been off eating table scraps, but they're still skinny. I guess it's nothing huge to worry about though, since their food is always there, and if they eat it only periodically, wouldn't that be considered grazing? If so, I guess that's only normal, since lots of dogs eat like that...