If you are referring to bug bite type stuff on the legs and ears you may be dealing with mites. Mites can be a front runner for greasy pig but essentially GP is a skin staph infection. I would talk to your vet about doing a skin scraping to test for mites or to just go ahead and treat for them with Ivermectin.
If you look up greasy pig on google.com and then look at pics theres a black pig in the second row of pics. My pigs have that on there back of ears and between there legs.
I've been dealing with GP for a few weeks now, not sure if it was a primary or secondary issue on a 60#er. We BBQ'd his twin brother and then he got melancholy, stooped eating, hunched back, wobbly and then no dice. Wouldn't move and developed abscess and major gross GP . Treated with isolation, penicillin and serious daily cleanses with iodine, peroxide and anti microbial washes and now seems to be good to go. But we have a litter of 2.5 week olds and don't want to bring him back to the heard (even separated by fences).
I've read that they really wont amount to much after this and in bad cases the liver and kidneys are damaged. Anyone have any thoughts on food quality and/or contagiousness on this guy? Drugs have run the course and should be out of the system according to the packaging. A little on the skittish side for food but hate to wast him.