I used to train a Greyhound that would refuse to get off her bed if she could hear rain on the roof - kennel kept dog, would never soil inside - her record was only getting off her bed to eat, not going out, not weeing or pooping for four and half days! We even carried her outside twice a day to let her go to the loo and she remained in the curled up, nose under tail position when put on the wet ground! Simply stayed where she was until lifted back inside her kennel where she would shake herself dry, have a drink and then jump back up to her bed and snuggle back into the straw until the next time we forced her to move!