Yesterday Mrs. Drang had to take Sparrowbane to the vet. He was obviously limping and in pain in his left hind leg. We were afraid he'd gotten wounded in a fight or something.
Back at home now; no sign of a wound, but his left hind leg seems to had a muscle strain.
Obviously, he needs to stretch more often...
EDIT: Realized that, in my haste to get out the door to work, I included the picture but not the source.
Which is, of course, I Can Haz cheeseburger.