What do you do when your dog is Covered in Porcupine needles?

Make sure he doesn't have any in his eyes or mouth because then you'll probably have to have a vet extract those. For the ones on his skin you'll need a pair of pliers to yank them out. The real danger is the chance of infection if the holes are left untreated. For safety's sake I'd get him on an antibiotic from the vet, which is not expensive at all. Otherwise some neosporin on each hole right after you extract the quill may help in preventing an infection.