[pitlove]

It is highly unlikely that at just 14 weeks old your pup has already developed some type of food sensitivity.

All I can suggest is when you go to the new vet give a detailed time line of everything that has happened since you’ve gotten him. I would also contact your breeder and inquire as to if any other people who own your boys litter mates are experiencing anything similar. Changing his food too much right now will likely only cause further problems.

Edit: Also how old was he when you got him?