If his poop is not stinky, it means that it is not a bacterial infection, but his liver is not strong enough to digest heavy meals
. I'd push 2-3 garlic cloves to sterilize his guts just in case. Your puppy has reaction to dog food, he might have reaction to any artificial dog food. The trouble is that virtually no dog food producer can copy what canines eat in nature. Up to 4 months old the puppy receives what his parent regurgitates for him - half digested food. Up to one year young dogs do not catch large prey themselves, they prey mainly on small rodents. Even in the adult wolf, wolves mainly eat birds, mice and rabbits, not heavy stuff like wild boar, deer or lamb. Your pup's liver is too weak to work on beef or whatever this dog food has in it. At this age feed him cottage cheese, goats milk, raw chicken breast with rice and carrots, raw rabbit fillet meat and green beans, cooked fish with oats on the daily basis, and raw beef mince with pumpkin - 200 gramms once a week only. The sooner tou switch onto naturals - the quicker your problem would be solved.
Of course, you can look for cheaper than Buy Ardeng Rabbit Meat
, because some suppliers provide it specifically for dogs.