Anybody ever heard of this? I was always led to believe that they were harmless... Mazzie had them and they were never mentioned by my vet or instructor, and I wasn't worried about them.
No but they do really upset some horses. We used Dermafas on my friends gelding. It really helped him. He went from being sedated and twitched to allow it to be put in, to no headcollar just a treat within 3 weeks.