Help.. He has hurt his knee before and limped for a few weeks. The emergency room dr put him on anti-inflamatories, but this is strange. We woke up this am and he was just limping using 3 legs but it seems to have gotten worse! He has a vets appointment tomorrow morning anyway, and he's not in pain, but I'm worried. I gave him 1/4 of a baby asperine, but that really didn't seem to do much of anything.