Actually I've seen several cases where the prongs became embedded or punctured the skin. 2 on Animal Planet, and one in the news. Prong collars are a training tool. Not for tie-outs and there are warnings in bold print on the cards they come with. They are designed to pinch the skin. The dog's tie out chain is heavy enough to make it so he's being pinched all the time-on the back of the neck...it isn't even on his neck right. Prong collars being used incorrectly have been known to lead to aggression issues due to the frustration of being pinched too often or constantly. I would like to call the ASPCA on them but since the dog hasn't been injured yet, there's nothing they could do. I do want to talk to them...but I can never get ahold of them. Even tried calling them today to let them know I almost hit one of their calves in the road, and they had a horse loose in the road. No answer, no call back. And they had this poor dog in a pitch black horse stall today. He was just howling and howling for someone to let him out. I took the prong collar off him, it's too tight on him as it is. Unbelieveable. Why have pets? Then I disovered 2 rabbits in a cage in another stall in the back of the barn. No food No water. I gave them water and they were still drinking when I left the barn. I also gave them some carrots I brought. *sigh* Why do people get pets if they are going to leave them in pitch darkness all day long? What a miserable existance! Sorry this is way off topic but I'm just very frustrated with these individuals. Especially the dog situation. A prong collar is a training tool, not for tieing a dog out. At least a nylon collar has support-that's why dogs can pull so hard with them and not with a prong collar.