I know someone who has a tiny dog that is litter trained. It actually works well for them, because when they're not there during the day, they just block her off in the kitchen and she goes in it. The only problem is, she doesn't like to go in the litterbox if it's not "clean". She'd rather go on the floor if there's something in her box. ((But I doubt this is a common habit...haha!)) Best of luck!