Bringing cats on high-speed trains is not allowed. Whether you put your cat in a backpack or a cage, it may be stopped by security staff during the security check because pets are prohibited on high-speed trains.
If your cat needs to be transported to another location, you can ship it to the appropriate destination. Cats can be transported by plane or train. To ship a cat, you need to bring its vaccination certificate, rabies vaccination certificate, and health check report to the animal health supervision agency for inspection and approval before you can complete the shipping procedures.
