Use a heating pad but on very minimal heat.. heat it up and then unplug it and hold it gently against karubi's hips, as you lightly with little presure assage thruough it.
I also heat the oven to 200, then turn it off. I fold a thick towel, and put it in the oven with the door cracked a few inches. I leave the towel in there for about ten minutes and then do same as i described with the unplugged heating pad.
Gentle massage with sympathetic sounds from the owner will help acknowledge the discomfort.... form a bond... and give dog confidence to move about.
I make the warm pad/massage time desirable by kissing dog as I rub and talk. When done I give a treat, and remind him he is loved, and he is a good helper!
The dog here at home with the joint trouble does not care to get on our bed with us that much, but we encourage him to lay on the bed to make the contact easier(since I can not bend to the floor.)