i know what it's a treatment for, but what I was asking is how do you know your pig has mites? If they are scartching or losing hair that doesn't definitely mean they have mites. There are several other things it can be. You need a skin scrape to diagnose mites. This is why your veterinarian wants to see you. We treat several guinea pigs at my practice and we see a lot of fungal infections, and bacterial infections- all with the same symptoms of itching, alopecia, and eventually redness to the skin. It won't hurt if you give ivermectin and it isn't mites, unless you overdose. If you do end up having to give ivermectin, you may want to ask your veterinarian if they can add flavoring to it- we do with ours and the guinea pigs are much more eager to take it! We also see a lot of sucess with advantage multi on pigs w/ demodex- however doesn't do much for pigs with scabies (those are the two kinds of mange mites; another reason to skin scrape; make sure you are treating for the right one). I hope this helps you.