My Sheltie, Gracie, is also experiencing the same challenges. My bedroom is in the basement and the stairs are not well lit. She goes down there because it is cool and then is hesitant to come back up. She yodels and I have to encourage her to come up. She has stumbled a few times and hit her chin, and that has damaged her confidence a bit. We have put Christmas lights on the wall along the edge of the stairs and that really seems to help her. But like yours, she is otherwise active. She is way too heavy for me to carry up the stairs, she weighs over 35 lbs and I am arthritic and have trouble with the stairs on my own. I hate to think what will happen when she can no longer navigate them on her own.

She is only 11.