We seem to have two tags for the same thing.
Issues related to housebreaking, training a pet to use certain areas and problems encountered with toileting issues, such as marking.
Refers to the indoor place set-aside for felines or rabbits to do their business.
The only difference is that one is used for dogs, and the other for cats. So should litter-box be a synonym for toilet-training? Looking through the questions tagged with litter-box most seem to be combined with the toilet-training tag anyways.