It's almost impossable to diagnose what is going on over the forum, with that said, we show, and I do realize that most show/training barns clip their horses now with a #30 all over. Once someone started doing it, now they all are doing it. someone said last year it was to show off muscles better! Well in my opinion, only use a #10 on the body, if you want to use a 30 or 40 on bridle path, face, pasterns, that is up to you, actually we place very well in the show ring without the extremes. When you us a #30 on the body the horse is more prone to sunburn, not to mention if the blade was used before on another horse, you could spread something if the blade was not disinfected. Also it may get very hot causing clipper irratation. Young horses such as weanlings and yearlings still have sensitive skin, so are effected more often then older horses. i've encountered the pig hair before and recommend as I stated before, a really good bath, any soap will kill bateria, then reclip using a #10. If it is lice you will see them, if it is fungus you will see round patches or black spots or even scabs. Then if you see that treat accordingly.