Cocker sleeping habits!!??

Question
I have a cocker spaniel and a cat. I've had them for about a year and all of a sudden, my dog has started sleeping in my cat's litter box. She doesn't eat out of it or use it as a toilet, she just wants to sleep in it. She started this about 3 or 4 days ago and has NEVER done this before. I'm wondering what has caused her to want to sleep in the litter box. Any thoughts???

Answer
Oooooooh!  Is it one of the enclosed ones?  Dogs like an enclosed places to sleep.  Does she even fit in it?  Perhaps pick up a plastic dog crate.  Look for one just big enough for her to stretch out in.  You could leave the door open or even not use it at all.  If she has a bed, put it in the crate along with some of her toys.  You could feed her in it.  Praise her for going in it.