I recently picked up a new family member from the local shelter, a young (maybe 4 yo) yellow lab. He’s a great guy but he comes with digestive issues. He didn’t fare well in shelter life and lost a lot weight. Not sure why, maybe stress, maybe food responsive enteropathy.

So, they put him on a hydrolyzed diet, and he seems to be thriving on it. Only problem is hydrolyzed food is beastly expensive and he eats like a horse. The vet suggests keeping him on the hydrolyzed until we can’t see his ribs anymore then slowly work in something else. He’s just about there now, he’s gone from 63lbs to over 75 now. Still skinny but much better.
Anyone familiar with this type of issue? Any alternatives to the hydrolyzed dog food, or what should I try next? The vet doesn’t seem too sure about his issue.