My cat went missing on Monday night about 8. He came back 24 hours later. We were happy to see him, fed him and he curled up in his bed and slept. I’ve been out at work all day and it’s only this evening that I noticed a little spot of stained fur on his foot. I investigated his paws and he has worn away all the claws on all of his paws! 
Front and back. There is a blister on one of his pads too. Some of the claws are just shortened, but a few of then are worn down to nothing". One of his back ones he won’t let me touch too much. There is either dirt or dried blood around quite a few of them so it’s difficult to see.
I’m assuming he must have been trapped somewhere And has worn them but scratching to get out. I’m going to take him to the vet tomorrow but is there anything I should be doing in the short term. He’s a big boy and difficult to hold so I don’t really want to pin him down and wipe his paws. I feel so guilty for not noticing this morning and taking h8m to the vet today 