I had to help a friend give a cat a bath once. It literally turned into a cylinder of pure muscle that I could barely control. Plenty of scratches and blood.
Even well cared for, domestic, gentle-natured cats can turn quite vicious when they don't want something to happen to them. We run that gauntlet every three weeks or so when our two needs their claws trimmed.
You just have to sit on them ... At least that worked for us ;) Our cat just yielded (protesting but not fighting) in this position. I'm sure you're aware but make sure you're just trimming the dead nail part.
