Phobia / Bad Behavior

Riley took me by surprise today by acting out a new neurosis. So far he's been a typical puppy. But yesterday was a rainy day and he would not go outside. He refused. If you dragged him you worried his paws would bleed on the pavement. I wish I Cesar Millan lived nearby. I see him cope w/ these kinds of behaviors all the time on tv, but I can't duplicate it. Now today, whenever Riley saw shadowy pavement, he thought it was wet pavement and refused to move. I refuse to cater to this behavior and I made him go thru it. He dragged his paws and I'm worried he's going to hurt himself eventually. I found if I make him RUN thru it, he goes. But I shouldn't have to run every time there is wet pavement. I insist he behave normally. I know these phobias and behavoris can be conquered, I just have to find a good trainer or animal behaviorist to help me.