Turns out he had a benign skin tumour which is good news. The vet said it was a good thing it was taken off. It got very big very fast! Jaspar gets his stitches out Monday -- they are dissolving stitches but they want me to come in anyway. He's been pretty good with his foot -- the bandage came off Monday to reveal that cavalier feet are not very attractive when shaved! He's licked at it a bit, but not nearly as much as before he had the thing removed.
I'll be glad when he can get back to longer walks as he has a lot of energy going nowhere!