[Ellie May]

Well, first there is a "very slight" chance that it is a medical issue if Max is usually the first one to get the idea to eat.

So, after eating all of this is he getting fat or is he skinny?
If he is eating all of this and is skinny, would look at pancreatic insufficiency.
Has he been cleared free of worms?

How much do they weigh and how many calories does 1 cup of the canned food contain. Ellie eats probably over a cup of homecooked a day and isn't getting fat because it is almost all moisture...no calories. You could figure their optimal caloric intake and give food accordingly, but all dogs are different, so it could vary up to 50%.