My son has a retired racing dog, and it's a fascinating animal. He's visiting with it for Christmas. Very quiet and mild mannered dog. We had deer in the backyard this morning and it seemed to think they were bigger greyhounds, watching them from a window and wagging its tail. In its racing life it never dealt with stairs, so despite training it struggles, and generally avoids them. 1-2 stairs is the most it will climb. So, it either has to go around them, or be carried up them.