Go to the begining of the movie. As Jack picks up the dog, (Verdell,), the dog starts whizzing all over the place. Look very closely and you'll see that the 'whiz' is actually coming from one of the fingers in Jack Nicholsons' gloves. I guess a tube or something was hooked up through the glove. The funny thing is that once you notice this for the first time, you'll see that the whiz is not even close to, well, where it 'should' be comming from, ie, Verdell!! Kudos to the 'whiz-rigger' for the color!! spot on!!!!

Enjoy!!