Conditions Ringworm.

You can attempt to treat yourself using an over the counter fungal cream or you can take him to the vet, and you to a doctor.

See https://www.guinealynx.info/fungus.html. You can treat yourself and the pig with the same stuff.

The cream you get is the stuff you'd get for athletes foot. You can get it at walmart or your local drug store.

Like mentioned before, it's just athlete's foot cream you put on ringworm. However, I thought I'd mention that if it doesn't improve after a week or so, go to your dermatologist; it's likely not ringworm, but pityriasis rosea. I thought I got ringworm a couple years ago, but it was actually that. It's a virus that spreads easily in spring and summer months. Unfortunately, I hope for your sake it is ringworm because pityriasis rosea has no cure because it is a virus just like the common cold, and can last for several months. I developed mine in February, and had it for almost 8 months. It's incredibly itchy, too. =/