I had heard that chihuahua owners use litter boxes due to their small bladders (thus needing to go very often) and also because in the winter they don't like to go outside.  Well, I use the litter box but he will only go in there about 6 times out of 10.  I have tried to give him lots of praise when he does go in there, but it doesn't help.  Also, WHEN he DOES go in there, because he is a 'big boy' and lifts his leg when he pees, it sometimes goes right over the edge onto the floor anyway.  I am starting to wonder why I even bother because it seems like I am always cleaning up after him anyway! 

Does anyone have any ideas or tips for chihuahuas?? Are they able to be trained to go outside?? Are there litter boxes with extra-tall walls for 'big boys' who lift their legs?? HELP!