A Dogs Life

Hello sent a search about my my Saint. Came to this site.. Sherman has gone down the basement stairs and refuses to come up. He has done this once before and my husband carried him all the way up!! He was about 135 pounds then,NOW he has gained a few more pounds and he's unable to carry him. I really have tried numerous things. We have one other dog that goes up and down with NO problems, so I tied the leash to him to pull and encourage...NOPE the Saint doesn't move. I put chicken ( he doesn't eat table scraps ) on the steps and he stretched as far as he could but NEVER took another step!! He is very determined to stay down there but man there is no way outside down there. I know it's cooler sooo should I just wait this out?? HELLLP