I just had to take my cat from myparents house to my very small apartment because my mom had very strong allergies. My parents house has a very big gardn, but they couldn't keep him outside. He was very close to my dad and only drank water when he gave him. He's never used a litter box, and its been a whole day and he hasn't urinated and doesn't want to drink water. I'm very worried, what could I do?