I think it is stressful for your dog when you bring a new puppy into your home. He was the only child, so to speak and now this new puppy is there and getting a lot of his love and attention.
I am sure you are, but make sure he is getting lots of love and maybe take him out potty a bit more frequently.
When I brought my 2nd and then later my 3rd yorkies home, the others were always very jealous at first.
__________________  Bella (I miss you)  Sachi Emmy |