Dear Sweet,
Is he on puppy chow?
Is he having diarrhea?
Does his abdomen look bloated?
Thank you.
There is a possibility that he has gas from the food change.
He may also have gas because he has gastro intestinal parasites.
As soon as you can, it would be a good idea to have a vet check his fecal sample for worms and other gastrointestinal parasites.
You can give him 1/8 of a gas-x tablet if his gas is really bad.
Veterinarian
Veterinarian in practice for 10 years. Compassionate, Caring, Experienced.