Each airline has its own policy, but here are some general rules:

1) Pets under 8kg can travel with passengers in a cage
2) Pets over 8 kg have to travel in a special cage in the cargo area. Only pats less than 32 kg are accepted in a cage in Airbus or Boeing aircraft.
3) Smaller aircrafts require dogs to be in a cage with a muzzle and leash. The airline needs to be notified 48 hours before departure.
4) Trained service dogs can accompany passengers with visual and hearing problems without a charge, though the charge for carrying pets on a flight is based on the weight and the fare.
5) Pets must be accompanied with a health book to show that all vaccinations have been done and they need to have a microchip identity and passport.

Preparing for the flight

Make sure you go on a long walk with your pet before the flight so that it is calm while restricted to its cage during the flight. In the car, ensure that you travel with the pet but keep it in the cage so that it can become familiar to this.

Make sure the pet is fed well before the flight and take along a favorite toy to sooth the pet.