OMG that is terrible!!
Thanks so much for the information Chachi. I will definitely have that checked out. He has had a couple of full checkups since I got him, is that something that would have been noticed then? He has made the noise ever since I rescued him and I've NEVER used a collar on him. Gosh, I hope he is okay until I can take him in tomorrow. It would happen a lot more often if he were close to death though right?