I'm glad to hear that Thumper's wound is healing.
It's hard to tell. They can do things like that as they get older, but if he wasn't doing it before...?
I did have one dog who had some issues after she was spayed. She had a small stroke during the procedure.
And, sometimes it has to do with how they feel. Has he seemed as though he's been in any pain?
Was he given any medications post-op?
Love All Life, Thank You For Posting! :)