My skinnies have had them a few times and been treated with oral Ivermectin and when this wasn't effective, by injection. I would not use spot on but then I would not use that on a hairy pig either but you will find mixed opinions on that. Also when Phoebe first had mites it looked like she had ringworm and it was only when she had a skin scrape that we saw a squished mite under the microscope. I am learning all the time with them, I have a lot of experience with skin issues in hairies but these 2 keep me on my toes. All our pigs are being treated for fungal at the moment and tomorrow the skinnies will have their first Imaverol dip.