First, Willy does NOT seem to have any pain at this time. I would not be addressing the issue this way if he was, believe me!

There must be some discomfort though, for him to sit as he does.

Elyse, he does fine on walks, and it does not matter how he does get to a down. I am more in the "what does this mean, do I need to follow up on this? position. I sent all this along to my Team Leader in the rescue late, late last night. They will need to decide if I need to pursue this with vet visits.

Anna, thanks, I had no idea what the possibilities were, I could only think of hip issues. Odd that an ACL issue could impact the sit, to me; I don't know much about dog anatomy, lol!

He jumps up on the chairs, and down, with no issues, no pain or limp, no wincing etc.

As I said, I've let the rescue know. I decided if I was concerned enough to ask here, they needed to know as well, what I am seeing. I know the rescue HAS done the hip surgery for young dogs. Among the top folks at the rescue, they have seen a lot more issues than I have and ultimately, they have to decide how to spend money for me to proceed, anyway.

If Willy had a vet visit already set up (like a follow up for his eyes or some such) I would ask the vet. As it is just now, he has no vet appts scheduled.