FlixBus runs an extensive network of budget intercity coaches across Austria and to neighbouring countries, which makes it tempting to assume as a cheap transport option with a pet. FlixBus's own official support page is explicit that this access is reserved exclusively for people with a disability or reduced mobility travelling with a certified dog — an ordinary pet dog or cat simply isn't accepted on board at all, regardless of carrier or size.

For a genuine service or companion dog, the requirements for a European route (outside the UK) include a medical or official certificate confirming a permanent need for assistance, with a service dog also needing proof of completed guide-dog-style training; FlixBus asks that its Customer Service team be contacted at least 36 hours before departure to arrange this. These dogs then travel free of charge.

The practical takeaway for most visiting pet owners is straightforward: if your Austria trip plan involves a FlixBus leg with an ordinary pet, it's worth replacing that leg with an ÖBB train journey (covered in its own article), a driven route, or a dedicated pet-transport service instead, since FlixBus itself won't be an option.