Both wild and tame rabbits spray urine to mark their territory due to hormonal urges. This behavior can often be curbed by spaying or neutering the rabbit.
If the rabbit cannot be spayed or neutered, extra litter boxes can be placed inside the cage to catch any excess urine that is sprayed. Urine spraying can also be a behavioral issue that occurs because a rabbit does not feel comfortable in its surroundings. Acclimating the rabbit to any changes that have occurred can help alleviate the urine spraying.