I just started walking my yorkie without his rabies shots too. I felt so guilty the first time, but I wanted him to enjoy the day and see how much fun the world outside our house could be!
I've noticed that it usually takes about a block to block and a half where Mojo is obsessed with every single plant, but then he seems to really get into the walk. I constantly talk to him and tell him how good he's doing. I also break into a quick jog for several seconds just to get his attention and get him excited. It's definitely an experience. But he completely passes out when we get home and I get a much deserved break!