My Cat Has Something Red And Swollen On His Dew Claw Which That Doesn't Seem To Be There Anymore,hes Limping And It Looks Infected?

If he is limping than he is in pain and if he is in pain than I would take him to the vet...do you clip his claws?? Sometimes the claws grow around back into the paw...this is very pain full for a cat and it would cause him to limp...check and see if his claws are coming out and retracting properly...