Our neutered white GSD slipped on our stairs and is now afraid of them. What can we do to help?

Your Q&As are extremely interesting and helpful.

We have a three year-old male neutered white GSD named Trigger.? He can be a bit fear-based dominant and aggressive (I have your DVD). We are working on this aspect of his personality and making good progress.

We would appreciate your advice on one small issue. Our bedroom is a duplex. There is an open staircase from the first floor where we have our home office and the second floor where the bed is located.

By open staircase, I mean the steps are wood, but there are no risers behind them. When Trigger was about a year old he was going up the stairs and on the second step he slipped and hurt himself (not badly). Ever since then, when he comes to the second step, he gets very agitated and goes back and forth until he works up enough courage to charge up the stairs. He has no problem going down the stairs. He also does this on other stairs that do have risers, but to a much lesser extent. Is there some way we could help him with this phobia?

P.S. We have your marker training DVD on order.

Thank you,

Joel