We rescued a pup from an animal shelter about a month ago. The animal shelter said that the pup should not go outdoors until he has his rabies shots, which are scheduled for June, when he is old enough. He is now paper-trained and goes indoors. We were told by others to get him used to going in our private backyard. He refuses to go. He is afraid of the outdoors and scrambles to come inside. As soon as he gets inside he goes on the newspapers. I think I have the only dog who comes INSIDE to go to the bathroom. Any advice?