High-speed trains do not allow it, regular trains do but only with immunization certificates
No, pets must be checked in as cargo, preferably through companies specializing in pet shipping, otherwise they might die,,,
Pets can only go in freight compartments, and high-speed trains do not have freight compartments, so in theory pets cannot be brought on high-speed trains. Shipping means your cat is transported as cargo; don’t expect it to travel in the same carriage with you, nor expect it to arrive as quickly as on a high-speed train. Basically, it’s like sending your cat by courier, the only difference is it won’t be delivered to your door—you have to pick it up at the train station.