My Lilly does that on occasion too, but I usually attribute it to her chewing too much on the toys or bones during the night. It hasn't happened often enough to consider it to be a regular problem, but it is worrisome when you know that it has to make them uncomfortable. And of course, when you don't hear it happening, you usually find it by stepping on it.

If it isn't happening frequently, it just may be something Cookie is nibbling on that doesn't settle right. If your vet is satisfied that she is healthy, she probably is.

Logan