So your pet will feel good during the trip, please observe the following guidelines.
Every airline has its own rules on flying with pets. As a general rule, dogs and cats weighing up to 6 kg may be taken on board inside a suitable kennel. You are responsible for making sure that the kennel does not exceed the maximum weight and measurements stipulated by your airline. Please note that many airlines do not allow certain kinds of animals—e.g. birds and rodents—to travel in the aircraft's cabin. Instead, they must be transported in the cargo hold. So please contact your airline well before your trip to find out what its rules and requirements are.
For loading into the cargo compartment, a rigid plastic or wooden crate, kennel, or container is mandatory, and it must contain bowls for food and water and be lined with absorbent material. Each animal must have enough space to turn around normally while standing, to stand and sit erect, and to lie in a natural position.
To facilitate traveling with pets, since October 2004 an EU directive has required every animal to have a standardized pet passport. This document can be obtained from any authorized veterinarian. It contains information about the animal's state of health and verifies that it has been vaccinated against rabies.