If you're taking your cat on a long-distance bus trip, it's generally recommended to place them in a suitably sized carrier. If the journey is longer than 4 hours, it's advisable to stop feeding them 2 hours before departure to help prevent them from defecating.
However, this cannot completely avoid it. It is still recommended to carry deodorizers, wet wipes, and plastic bags with you to clean up dirt in time and keep the air fresh.
