Nebo is acting fine this morning. He's 4 years old, he'll be 5 in May. He has a combination of metal and plastic tags, but its not the tags she chews on its one of these (the tags are inside) It is a new one I just put it on a few days ago, she chewed up the old one so bad I threw it away. They are $8 a piece so it's getting expensive. I don't know if I dare try anything else, I'll just buy more tag holders after she kills them...I just want Nebo to be ok.