I have 3 yorkies, Jazzi is 1 1/2 yrs. and Auggie and Roxy are both 3 yrs. Do you think they're too old to litter train? Also if they're not too old will I need more than one box? I really don't want to line my walls with 3 boxes. I wasn't sure if I should have started a new thread or just be a Budinski with my question on the same subject. So I chose the polish kid.