My horse has 4 lumps on her shoulder that I first noticed about 2 weeks ago at a schooling show while I was petting her. One is rather large and the other three are small, about the size of peas. They are hard, don't hurt her and can be moved around. The big one had a little scab on it, but other than that my horse had no other markings to suggest what could have caused them. Our vet is coming on Thursday to vaccinate some horses and we are going to have him look at her then. Hopefully they are not a big deal, but would anyone have any idea of what they could be?