It is not recommendable to put a dog alone into the hold, between other anmals, strange smells and loud noises.

Therefore, only cabin transport is acceptable.

Begin with only short flights, and slowly increase the distance/duration.

Get the dog accustomed to the crate before taking off. Play typical airport and flight noise already at home. Visit airports already before any trip. Have familiar toys and small win the crate. Hydrate the dog the day before the trip but reduce food and water appropriately before the trip.

Night flights avoid pit stops.

Have a pee mat with you.

Iberia is pretty representative for airline I would use, such as Lufthansa, Air France, British Airways, Air Europa…
Your pet can travel with you in the cabin if it meets the conditions explained below. You must show proof of compliance to the agent at the check-in desk, who will fill in the official IATA form.

• A maximum weight of 8 kg, including the container.
• The maximum container size is 45 cm (length) x 35 cm (width) x 25 cm (height), and the sum of these dimensions must not exceed 105 cm.
• The pet crate must be well constructed and ventilated (at least 16% of the total surface of the four sides), with a safe, leak-proof floor and soft sides able to be compressed.
• You are responsible for the pet travelling with you and you must ensure that it does not provide inconvenience to nearby passengers. In addition, your pet must remain inside the container for the duration of the flight.
• We do not accept animals with special characteristics, e.g., a strong odour, etc., that may provide inconvenience to other passengers and the crew.
• For safety reasons, you cannot travel with your pet in a seat next to the emergency exit.