I agree with Barb04 - of my 3 dogs, one of them is particularly strange. He only eats when i am around him. At times, he just refused to eat - even if i offer bone treats. Like Debi, i also have to add different things into his food to entice him to eat. Sometimes, he will go to our plants and eat the leaves - yes!! He decided to be vegetarian!
Nowadays, after reading this board, i just feed him Kibble and canned food / some homecooked food. On days that i feel that he will not eat his food, i will give him raw chicken necks. He eats his food more regularly now though not all meals. So long as he doesn't skip too many meals, he will not have gastric.
I also noticed that if he has diarrhea / constipation, he will not take any food. During such times, i put some manuka honey and apple cider vinegar to their water to soothe their stomach.