'Banding' is routinely done not only to calves but lambs. Judging by my poodle's reaction to inadvertent banding of her tail, it hurts *only* when it slips off prematurely.

My little daughter put a rubber band on our dog's tail to hold on a ribbon or flower or something and didn't take it off. I knew nothing of it until a week or so later when I was brushing the dog and found it. Naturally, I took it off - and was horrified at the pain she felt. I cried, my daughter cried, my dog was in helpless pain for a good 15 minutes.

A couple of days later her tail fell off and she had only a three-inch long tail the rest of her life.