Oh Sana! That's awful! Poor One Down! I'm pretty sure that if he doesn't let you touch it, it's more serious. Mz Logan has a bad right paw, always jumping wrong off the bed or running, and she'll lift it up. I can massage it with no problem. The vet couldn't find anything. Maybe it's a constant strain. I hope One Down will be OK and that you can get the poor boy to the vet. Keep us posted!