Whether you’re planning an international move, taking a long holiday, or simply can’t imagine leaving your cat behind — yes, flying with cats in-cabin is possible, even on international flights.

I moved from Portugal to Brazil with my two cats (and many, many suitcases), and I’ll walk you through how I made it happen. From airline rules and carriers to the unexpected stress and clever workarounds. 

Boarding is taking place. Please, proceed to the gate.

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The Departure: Leaving Porto

My departure would be from Porto, Portugal, to Rio de Janeiro, Brazil. That’s when trouble started to stir. Most European airlines won’t allow pets over eight kilos in the cabin, which can be a problem if you’re flying with cats internationally, especially one on the heavy side. Your cat carrier, plus your pet, can’t weigh over eight kilos. Which, believe me, isn’t a lot for most animals.

Luckily, we found an alternative. There’s a single airline, Azul — which is Brazilian — that increased pets weight in 2024, from eight to ten kilos. Still, my cat surpassed that mark and needed to drop some grams before our flight. On this post — Best Pet Friendly Airlines That Allow Cats to Fly In-Cabin (2025 Guide) – I talk about your options and the best recommended companies to travel with your cat. A small detail, too, is that Azul Airlines didn’t operate in Porto in April 2025*, the date of my flight. All their flights left from Lisbon and, then, as all other companies only allowed a limit of eight kilos per pet (and carrier), I was, once again, stuck.

Flying with cats in-cabin means considering not only airline restrictions but also how to get to the right airport with them safely. So, as my only option, I decided to rent a car and drive all the way from Maia — the next city to Porto — to Lisbon, spend the night there and fly the next day. To add to the level of difficulties, there aren’t many companies who allow renting a car in one city and delivering it in another, and expenses tend to get higher, too. My choice was Record Go Mobility, a Spanish car rental company operating next to Sá Carneiro airport. 

* Azul Airlines will resume flights from Sá Carneiro Porto to Viracopos São Paulo, and add a new route from Sá Carneiro, Porto, to Guararapés, Recife, starting on June 2025.

Arriving at Record Go, I was frightened there might be hidden expenses or issues with the rental, but everything went smoothly. I left a hundred euros deposit for automatic highway tolls and another hundred for gas. Once I brought back the car to their shop in Lisbon with a full tank, they would refund my gas deposit, plus the remaining money from the toll expenses, in a period of 30 working days. Luckily, all went well and the money was refunded on the deadline. I highly recommend their service, by the way. It was the cheapest rate I could find, with flexibility to leave the car in a different city, only rent it for a day, plus all went well with the refund.

Pet Carriers: How to Find The One

When flying with cats in-cabin, choosing the right backpack is crucial — it needs to be lightweight, flexible, and airline-approved. Measurements differ from company to company in accordance to their aircraft models and seat disposition. Azul Airlines is assembled in a way that pet seats, usually located by the window, are slightly more spacious. During your flight, you’ll place the carrier under the seat in front of you, where your pet will stay. The spot is small and not too deep, unarguably, your pet will rest between your feet and you won’t have much space. That’s a small price to pay to have them with you.

Dimensions and Rules

Azul Airlines’ pet carrier measurements are, specifically, 20cm in height, 31,5cm in width and 43cm in length. You can choose between rigid and malleable containers, but for cabin flight, employees themselves advise on fabric and nylon bags or backpacks. When the carrier is flexible, it can bend and fit under the seat, therefore cabin crew and check-in staff are more understandable. If the container is rigid and made of plastic, it must strictly follow those measurements, as it won’t fit in the space if it’s slightly larger.

The Best Backpack for Flying with Cats In-Cabin

Once I was assured by the call center employees that I could bring a slightly larger pet carrier — as long as it was bendable — I began my research targeting weight instead of size. Most pet carriers are heavy, from two to three kilos even when made of lightweight nylon and mostly breathable net. The lightest and largest cat backpack I found for flying with cats was from Temu. It cost me around 30€ and was delivered to Portugal within two weeks. I ordered one first, tried it on my largest cat, then ordered the second one.

You can find pet carrier backpacks similar to the one I bought on Temu on Amazon Brazil. This grey one is larger but still malleable, and this one has several utility pockets. This one from Aerial seems to be the official choice for anyone flying in Brazil, according to my research on Brazilian forums.

Although the base isn’t as sturdy to uphold a large cat sitting down, it was well-made and secure, allowing me to carry them on my back or front while I could still drag suitcases with both hands. There’s a front pocket, which is very helpful to carry their passports, documents and snacks, and a side curtain to open and close a netted panel. I did try other pet backpacks, but they were heavier and too tall to fit the underseat compartment. They are great for vet visits, though.

Considering my oldest cat is overweight and on a diet, I cut off the front pocket and the side flap, subtracting 700g from the total weight. I mean, any lost weight is a win when there’s a weight limit! 

Extra Tips for Flying with Cats In-Cabin

There was no issue with the backpacks at the airport, no one measured anything, only weighed them. I was a train wreck at this moment, as I’ve heard stories of people being stopped from boarding with their pets due to weight restrictions. Thankfully, all’s well that ends well. 

One final tip: remove any linings and bases from the backpack, if you can, before heading to the check-in counter. You can reattach them later, a few grams won’t put anyone’s safety at risk. It’s best to prevent going over the weight limit and being denied boarding.

Adapting Your Cat to the Carrier

Understanding Your Cat’s Personality

The expression “scary cat” doesn’t come out of nowhere. Cats are wary by nature, some even with their tutors. That’s the case with my youngest cat, too. Lucy was adopted when she was fourteen-ish months old. I met her at the shelter where I volunteered and brought her home. She was tender and loving, but suspicious and, up to this day, over five years later, she runs from me when I try to catch her. 

That’s why it’s important to adapt your cat to its new carrier, especially if you’re preparing your cat for a long international flight. Some strongly dislike being trapped or get nervous about the possibility of leaving the house. Others enjoy the tight, comfy space, but will start screaming once they’re put in a car (personal experience).

Step-by-Step Adaptation Process

Adapting your cat to the carrier in advance is one of the most important steps when flying with cats in-cabin, especially on international routes. When the new backpack arrived, I aired it out. I literally left it outside, on the balcony, in the sun. Sometimes we smell plastic or glue from when the product was being assembled, and even the faintest scent can put a cat off. After that, I left the backpack open and available on the floor of the living room, with one of my tops in it. They just looked, they didn’t want anything to do with the bag, but it’s part of the process. They need to acknowledge it and get used to it.

Next — and this is a big step — I would spray some Feliway in the backpack, close it for a bit, and, finally, put my cat inside, zipped in. Feliway is made of synthetic cat pheromones, which, in theory, relax them. Its use should be constant as results are progressive, so I’d repeat that every other day, increasing the time I’d leave my cats in the backpack. I’d never leave them for too long or force them to stay in if they showed too much stress. Eventually, they started taking naps in the open backpack. I brought the spray with me for the flight but didn’t use it. My cats stayed in the backpack willingly, probably because they were nervous and felt safer there.

Documentation: The Boureaucracy

This is the most annoying part of flying with cats in-cabin to be allowed in Europe or the USA. There are several steps to take when preparing documents for traveling to Brazil with cats. There’s vaccination, pet documentation, veterinary certificates — all tied by excruciatingly tight deadlines. Also, bureaucracy changes depending on the country. That’s why it’s imperative to have a trusted veterinarian to assist you through the process. Luckily, the whole team from Catassol Veterinary Clinic, in Maia, Porto, was extremely helpful and empathetic, assisting me in every step. Whenever something was too complicated or sounded off, they would take matters into their own hands and make calls, confirming the updated process, and advise me on what to do next.

In a separate post — How to Bring Cats to Brazil: The Paperwork You’ll Need (with Screenshots) — I explain step-by-step what you need to do (and in what order) to get all the papers, health certificates, and vaccinations ready for your trip.

What to Pack for Your Cat

You might have noticed that I’m on the team of “it’s better to be safe than sorry”, so when it comes to flying with cats in-cabin, it’s best to bring everything you could think of.

Every passenger is allowed one small bag in addition to a ten-kilos suitcase, plus the pet carrier, which you paid for. This is standard, everyone gets that extra bag, no matter if your pet is taking the bag’s place under the seat in front of you. I brought a backpack, as I usually do, instead of a hand or crossbody bag. That’s where I fit my whole life. No joke. If you’re wondering what to bring when traveling with cats in-cabin, here’s a full list of what I packed:

• Snacks
  I brought their favorite, which are those little, smelly crackers from Dreamies. They go crazy for these. Once in a while, I’d open their carrier and throw some in. It was more about soothing the nerves than feeding them.
• Churu
  I didn’t bring this one as my youngest cat doesn’t like it, but this is a great alternative if your cats are more into creamy snacks. As it’s a paste, it also offers some hydration, helping your cat if they don’t drink enough water.
• Foldable litter box
  This was a game changer. I had no idea there was such a thing and it made travelling way easier, either by car or plane. It’s impermeable and easy to clean. I brought a little bag with some litter, so I could bring my cat to the bathroom, unfold the box and throw some in. This is great for long flights or connections.
• Disposable Pads
  In theory, these are mandatory. We used them to line their carriers in case any accidents happened (and it did happen, I’ll talk about it later!). I placed one in each backpack and brought another two, just in case.
• Portable water bottle and drinker
  Cats are not big fans of drinking water, especially if it isn’t from a stream or a bow, but this is a great option if yours isn’t too picky. You just fill the small bottle and press the button to release the water to the attached pot.
• Cat Harness
  I feared my cats would run away, so I bought a couple of harnesses. In case I needed to remove them from the bag in an inhospitable environment, I could use them to keep them safe and avoid them running away, scared. Remember to properly take measurements from your cat, most sizes run small and it’s safe to not make assumptions based on sizing labels.

Waiting for our Flight at the Airport

This, sir, was no joke. We left at four-ish in the morning, called a XXL Uber to bring my five 23kg suitcases plus cats, my mum and I. We had barely made it to the airport and I was already exhausted. Luckily, our Airbnb was close, so it took us less than twenty minutes to get to the company booth. We checked in all luggage, including our carry-ons, thinking it would be easier to carry just our backpacks and the cats. It wasn’t. And we realized that once we got our luggage in São Paulo. But that’s a story for the next topic.

Our Airbnb Recommendation Near Lisbon Airport

And if you’re staying in Lisbon and want to be next to the airport for an early flight, I highly recommend Hugo’s place. It’s spotlessly clean, there are amenities such as soap bars, shampoo and conditioner, the kitchen is fully equipped and there’s even a balcony if you want to relax outside or grab a cigarette. The building is brand new, you self-check in using a passcode and there’s parking right in front of it. It’s one of the most comfortable places I’ve stayed at.

Check-in Process and Cat Weigh-In

At the check-in, Azul Airlines staff asked for my cats’ passports. If I’m not mistaken, they never asked for DGAV’s or the clinic’s health certificate, which was to be shown upon arrival at our destination. Then, the moment of truth: my cats were put on the scale and weighed. I’ve never felt so nervous in my life. Nikolai battled to drop some weight over three months and he was still heavy. Thankfully, he was within the ten-kilo limit and he passed. Lucy is smaller, so she was easy peasy.

Chaos at Lisbon Airport

Humberto Delgado Airport, in Lisbon, is… something else. If you’re used to flying through Porto, Lisbon’s an adventure. It’s packed. It’s chaotic and busier than I expected. The signs are confusing, you can get lost easily. After fifteen good minutes trying to figure out which way was to the screening area, we found an elevator. We made it.

Going Through Security Check With Cats

Going through the airport security check with cats can be tricky. I was dreading this part. The part where you need to remove your cat from the carrier and go through the x-ray. I watched some videos online about people flying with cats in-cabin and they mentioned they had to hold their cats far from their bodies, stretching them out. First, one of my cats is very heavy, I didn’t know I could hold him safely and keep my arms stretched out. Then, my smallest is afraid of everything and she struggles when she’s held, she doesn’t enjoy it one bit. What if they asked me that and they ran away?

But they didn’t. They let me go through holding my cats against my body, nestling them. They were scared, so they cuddled up against me like the little babies they are.

Ok, everything is taken care of, right? Nah.

Boarding Gate Stress and Pet Policy Frustration

I arrived at the boarding gate and it was as crowded as the airport lobby. Screaming children, crying babies, people napping against their bags and absolutely no seats available. There were no more than twenty seats in the area, for a single flight that was clearly crowded. I had to sit on the floor, I was too tired from going to bed late and waking up too early. I’ve been carrying this anxiety over the past months due to what moving truly entailed: selling my apartment, shipping boxes with my personal items, weighing and separating what I was going to bring in the cargo hold, taking my cats to the vet, signing my resignation from my job, getting rid of the rest of my belonging, meeting friends. It’s insane what an international move really is about. I talk more about it in my post Why I Moved Back to Brazil.

Sitting on the floor, I played with my cats and petted them with my hand stuck in the carrier, while my mother grabbed us some water and snacks. Meanwhile, boarding had started and, during priority call, I spoke with the steward at the counter and people with pets were not considered priority. I found that frustrating. Everyone gets stressed out when they’re flying, especially internationally, but having a pet getting carried around and bounced in a carrier is stressful for them. Flying with cats in-cabin can be emotionally exhausting, especially during long layovers and chaotic boarding gates.

Seat Issues and Azul’s Aircraft Change

Once we got in, I didn’t know what to expect. The evening before, I decided to double-check all the information about the flight and found out our seats were changed. I paid for larger seats, knowing a twelve-hour flight is uncomfortable as it is, with a cat on my feet is even worse. They changed our seats to regular economy seats, even though we paid extra, without notifying us. I spent hours trying to speak with someone who would admit the mistake and try to help us, in some way. But, of course, nothing could be done, because, at the end of the day, they weren’t using that aircraft anymore and this model didn’t have any larger seats, only business class. So we had no other choice but to accept the refund and carry on — I explain everything in the post My Experience Flying with Pets on Azul Airlines.

As soon as we could, we asked if another passenger minded to exchange seats with us so we could sit side by side. We were randomly assigned seats upon the aircraft change and given all the stress, we wanted to sit together to keep the cats close to one another. Kindly, the gentleman from São Paulo accepted the seat we offered him, saying he, too, had a last-minute seat change. He was happy to sit by the window and let my mother take the aisle next to me. 

Finding Seats and Crew Support

A steward later explained to us it isn’t customary to allow two pets next to one another, that the pet seat was by the window because the compartment under the seat in front of it was slightly larger, so it could better accommodate the pets. But, noticing we were together, both with pets, she didn’t mind, realizing it was better not to separate them. She was kind. Indeed, the front compartment of the seat by the aisle was a bit smaller, but my mother was carrying Lucy, the smallest cat, so it was comfortable for both of them.

We were ready for take off.

Arriving in Brazil

Our flight went to Viracopos Airport, in Campinas, São Paulo, where Azul Airlines is based and flies all over, domestic and international. I had never been to this airport before, so, once more, I was in for a surprise.

People everywhere looked confused. There was no order and no one around to question anything. Luckily, I noticed the flow of people and easily found our path to customs, where we stayed for nearly an hour. Two officers checked passports at border control and whole families went together to the booths instead of lining up to keep things orderly. Most people didn’t want to risk losing their place in line, so they wouldn’t go through the eGate available right next to us, completely empty. My mother decided to wait in line with me, even though she could use her electronic passport, as she would have to wait on the other side anyway.

The Nonexistent Pet Checkpoint

Once we passed through the border control, we were worried about the time we had left to pass through vet control, grab my suitcases, recheck them and get to our connecting flight. Upon asking for information to airport staff, we found out there was no need for any documentation from the cats, that we were allowed to go to the baggage claim area. I couldn’t believe it. While it was great we didn’t have to waste time with that, I was appalled at the lack of control. I’ve heard stories of people facing lines to get a quick check-in from the airport veterinarian, both in Rio de Janeiro and São Paulo. And I wondered how I’d spent so much money with so many documents, to never have them checked.

We boarded our connection flight. Our stress was palpable and clear in our faces, although we felt extreme relief by the realisation we were nearly home. On this flight, our extra-comfort seats were available. It is a chunk of additional space, indeed. We were offered the airline’s signature snack and a beverage and, in less than an hour, we landed.

The Last Stretch

My journey ended after a thirty-minute taxi ride to my mother’s place. While my brother showed up only to drive all my suitcases to hers, we rode with my cats, sweaty and completely beaten.

I hope this guide helps you feel more confident about flying with cats in-cabin. It’s challenging, but absolutely worth it to keep your pets close.

Dear ladies and gentlemen, welcome to Rio de Janeiro.

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