The cat has cut his paw on the large pad on the underside (I haven't actually seen it as he turned 'bitey' when I tried and would only let his favourite human look at it). Will this sort itself out on it's own or do I need to be doing something about it?
It really does depend on the depth and, width and length of the cut. Tilly cut her paw once on a bamboo strip and she had to have it stitched and dressed, She also had to wear a padded sock to protect her foot. Best to go to the vets if it's bleeding and causing her problems.
Wash it in warm water 3 or 4 times a day and if you have an antiseptic cream or spray, then use this after washing and drying the paw.
Monitor the situation for a week and if it hasn't healed, then take him/her to the vet.
Fox attack that cost £3k at vets for 3weeks. He licked off stitches at home but the skin had repaired mostly. He finished dressings by licking & is now fine. Your cat might need stitches & dressings. He can cleanse debris itself if wound not too deep.
When I managed to get a get look at it it turned out that he had a small nick to the pad - turns out that he is a drama queen - he's right as rain now but I have some antiseptic spray for any future accidents.