Deutsche Bahn, Germany's national rail operator, sets out its pet policy directly on bahn.de. A small dog or other small pet, roughly house-cat size or smaller, travels free in a closed, secure, lockable carrier — a box, cage or carrying bag that fits under the seat or in the overhead rack without impairing other passengers.

A larger dog that doesn't fit in a carrier needs its own ticket, priced at half the normal fare — this applies across Flexpreis, Sparpreis and regional (Normalpreis) tickets, and it's booked by adding a 'Hund' traveller type to the booking online or in the DB app. A dog travelling this way, outside a carrier, must be leashed and wear a muzzle for the journey; assistance and guide dogs, and dogs accompanying a traveller with a severe-disability ID carrying the 'B' notation, are exempt from the muzzle rule and always travel free regardless of size.

A few restrictions are worth knowing before booking: pets (other than assistance animals) aren't allowed in the restaurant or bistro car, no seat reservation is possible for a dog, and several international routes carry their own rules — DB doesn't carry pets (except guide and companion dogs) on trips to or from the UK, Northern Ireland, the Republic of Ireland or Norway, large dogs aren't permitted on trips to Italy, and travel to Denmark restricts dogs to second class unless they're an assistance dog. For routes to Austria, Italy or Switzerland, a small dog's carrier is allowed to be slightly larger, up to 70 x 30 x 50cm.