Flying with a dog or cat: cabin or hold, rules and preparation

You do not make the choice, it is made by the sum of the animal's weight, the carrier's size and the airline's rules. A dog or cat whose weight, together with the carrier, stays within a set limit usually travels in the cabin, with the carrier closed and stowed under the seat in front of you. Above that limit the animal travels in the hold, in a dedicated compartment that is pressurised and heated, separated from loose baggage.

Many airlines refuse animals in the hold altogether during certain times of year or on certain routes, because of the risk from extreme temperatures on the tarmac. Some flat faced, brachycephalic breeds face restrictions or outright bans, precisely because they are more prone to breathing trouble under stress and heat. That is why the first useful phone call is not to a travel agent but to the chosen airline, with the species, the estimated weight and the date in hand.

The carrier is not an accessory, it is where the animal will spend the entire journey. It must let the animal stand, turn around and lie down without straining. A carrier that is too small is refused at check in, one that is too large will not fit under the cabin seat. For the hold you need a rigid, approved carrier with sturdy walls, ventilation on several sides and latches that will not open by themselves.

• Measure the animal for height, length and width before buying, and compare against the carrier's internal dimensions, not the external ones.
• For the cabin, check the airline's under seat size limit, which varies between routes and aircraft.
• For the hold, choose a rigid IATA approved model with a metal door, ventilation on at least three sides and bowls that clip inside.
• Attach a label with the name, your contact details, the destination and a live animal marking, plus a recent photo of the animal.
• Fix a pouch to the outside with a copy of the health documents, so they can be read without opening the carrier.
• Line the inside with an absorbent pad and something that smells of home, avoiding toys that could be swallowed.

For travel within the European Union you generally need a microchip, a European pet passport and a valid rabies vaccination, with precise waiting times between the vaccine and departure. Some countries add their own requirements, such as treatment against a particular parasite within a set window before entry. For flights outside the Union the rules vary greatly and must be checked with the embassy or the health authorities of the destination country well in advance.

1. 1

   Check the microchip and passport

   Make sure the microchip is readable and meets the international standard, and that the passport shows the correct details. An unreadable chip at the border causes trouble even when the paperwork is in order.

2. 2

   Confirm the rabies vaccine is valid

   Check that the vaccination respected the minimum required times before travel. If it has expired or is too recent, entry can be refused.

3. 3

   Ask the destination's requirements

   Some destinations require antiparasite treatments, blood tests or extra certificates. Find out months ahead, because some tests take a long time.

4. 4

   Book the visit for the certificate

   Many trips require a veterinary certificate issued within a few days of departure. Book the appointment early so you are not left without a slot.

5. 5

   Carry copies and originals in order

   Keep the originals with you and a copy clipped to the carrier. Logging vaccine and treatment deadlines in a digital diary avoids last minute scrambles.

An animal that treats its carrier as a refuge suffers far less on the journey. That habit is built over weeks of small steps, not through intensive training the night before. The goal is for the animal to walk in on its own, lie down and stay calm even with the door shut and the carrier moving.

1. Keep the carrier open at home with a comfortable blanket inside, so it becomes a normal place to rest.
2. Reward with food and toys every time the animal goes in on its own, never pushing it inside by force.
3. Gradually extend the time with the door shut, staying close at first and then moving away little by little.
4. Take short car trips with the animal in the carrier, to link movement and container without fear.
5. In the days before departure keep meal and walk routines steady, reducing solid food in the hours right before but leaving water available.
6. Let the animal relieve itself before check in and, where possible, use the pet relief areas found in many airports.

On the day of the flight arrive at the airport with plenty of margin, because checking in an animal takes more time and more steps than a bag. Stay calm: the animal reads your tension and amplifies it. Once on board in the cabin, avoid opening the carrier, and if there is a connection, check in advance whether there is time and space to let the animal stretch.

Most gate problems arise from overlooked details that could have been fixed earlier. They are worth knowing, because almost all of them are avoidable with one extra check.

• Booking the flight without securing the pet slot: cabin places are few and sell out quickly.
• Turning up with a brand new carrier the animal has never used, which it then refuses at the worst moment.
• Confusing the airline's rules with the country's, arriving compliant on paper but oversized on the carrier.
• Underestimating connections: a change of airline mid journey can mean different rules on the same itinerary.
• Feeding far too little before departure, risking nausea, or far too much, risking the opposite.
• Ignoring tarmac heat for animals in the hold, and the seasonal bans some airlines apply.

A separate chapter concerns very young puppies and kittens, older or unwell animals and short faced breeds. In these cases the flight should be discussed with the vet before booking, because sometimes the best choice is to postpone, change the mode of travel or split the trip into stages. Assistance dogs also follow specific rules, often more favourable, but they must be declared and documented to the airline ahead of time.