Im a new member just signed up today (saturday). I have just read this thread and tears have welled up in my eyes, Im so sorry this has happened to Cali, the poor girl. I had a Yorkie once who constantly tried hanging herself by her collar on the garden fence, since then I have never put a collar on my dog when she is home alone or not. It only goes on for walkies.
Please keep us informed on how she is I hope everything is ok