ahorn66,
He might just need more time or he might need less volume of the new food. One of my pugs took about 2 months on a mixture (25% old/75% new) before eventually going to a new food which happened to be a high protein, grain free food. And I didn’t know about probiotics or digestive enzymes or pumpkin or other fiber back then. Right now my foster pugs eat Nutrisca or Nutrisource grain free Lamb or Heartland Select and one eats some Brothers Complete. I give ground psyllium when they first come to my house to help them with their stools. But definitely add a probiotic.
