Hi to everyone. I don't know if anyone has had this come up but I thought I would see. We have been using a metal prong collar for about 3 weeks. It works great and I love it. But, yesterday, I added a link. I put the collar on this morning and left it on for about 4 hours. By the time I took it off there was a silver ring around my puppy's neck. And, I just noticed that he has lost fur around his neck in places. I gave him a bath and put neosporin on the sore spots. His neck still has the metal stain on the fur. Any ideas? I am thinking he is allergic to metal. Now, I am looking for a non metal collar that's as good as a prong.