Have you had him since a pup!?
My old Yorkie did that ALL THE TIME!
He was a rescue. when he was in his old home, he never was given water. So my vet said that when he gets it, he consumes too much cuz he is excited to have it. Then his tummy couldnt handle it.
So instead of leaving a bowl full of water out for him. I had to give him a little bit constantly throughout the day. |