Dr mom777
If a dog is quivering on the floor, use your common sense.
Dogs protest things in various ways in training. Some dogs get aggressive, some dogs simply ignore the handler, some dogs urinate, and some dogs fall on the floor in total fear. What you need to do is to be a firm and fair handler and IGNORE the dog's fears and train it normally. If you cater to its fears it will learn that it can get you to STOP its training when it shows it is afraid. Dogs are a lot tougher than any person on earth..it will be fine if YOU will allow it to be fine.