I would also give him Nutrical while he isn't eating. Lucy was so overwhelmed by her new environment (so excited) I had trouble getting her to focus enough to eat and my breeder said to give her Nutrical. I still give it to her if I notice she isn't eating alot. She just gets so excited when we're home she will forget to eat. Maybe hand feed a bit?
Oops. Senior moment. I see you are already doing Nutrical. My bad!