There's a better than even chance that if the owners panics when they do not eat dog food, and proceed to feed them table scraps, then the dogs are holding out for table scraps. In another words they have trained their owner well. Then you come along and give them the option of eating dog food or dog food. Their choice is sort of easy at that point- eat dog food or go hungry.

The fact the dogs have high energy eliminates a multitudes of possible health problems. You might suggest to the owners that they wait the dogs out. No table scraps period. The chances are after a couple days of hunger strikes the dogs would cave in, and start eating the dog food.