On domestic flights the rules aren't the government's — they're the airline's, and they're stricter than most people expect. The five things each carrier decides, and one fully worked example.
Where this breaks is almost always at the counter.
Someone turns up with the carrier they already owned, or the card on their phone, or a dog two centimetres taller than the airline they picked allows. And at that point there's no negotiating: the flight leaves anyway, without the dog.
Nearly all of it is avoided with one afternoon of preparation. This is that afternoon.
There's a confusion here that costs people a lot of time. On a flight within Mexico, the one asking for paperwork is the airline, not the government.
The SENASICA procedure — the one that comes up first whenever you search this — applies to entering or leaving the country with an animal. To fly from one Mexican city to another, what governs is the policy of the airline you booked.
That has an important practical consequence: the rules differ between airlines, and they change over time. There is no such thing as "the requirement for flying with a dog in Mexico". There's the requirement of the airline you're flying, in the week you're flying.
Every policy, without exception, is organised the same way. If you know what to ask, you can read any of them in three minutes:
1. Cabin or hold. Some allow both, and the line between them is the combined weight of the animal plus its carrier. It's the first question, because it changes everything else.
2. Carrier dimensions and weight. The number that surprises most people. It's measured with the carrier closed, and the weight is almost always combined — animal plus box — not the animal alone.
3. How many pets per passenger. Usually one in cabin. If it's two people and two dogs, that changes how you book.
4. What paperwork they ask for. The card, the airline's own forms, and sometimes a vet's certificate. Note carefully: these are the airline's documentary requirements, not a care schedule. What your pet needs and when is decided by your vet.
5. The restrictions. Minimum age, pregnant females, recent surgery, excluded breeds, and specific warnings for short-muzzled dogs. This is the section nobody reads and the one that ruins the most flights.
So the five questions aren't abstract, here's what they look like answered by a real airline. This is what Volaris publishes on its official site — link at the bottom — and it's a reference for shape, not a universal rule:
That last block is the one worth reading in full on their site before you book, because the breed list is explicit and isn't open to interpretation at the counter.
We could. Almost every article on this does.
We don't because those tables age badly and read as though they don't age. Dimensions change, forms change, breed lists change, and a two-year-old article with concrete numbers is more dangerous than one without: it gets you to the airport feeling confident.
What does work: open your airline's page the week you book, with the five questions above in hand, and write down the answers. The official links for Aeroméxico and Viva Aerobus are at the bottom, along with Volaris.
If an article — this one included — and the airline's page disagree, the airline wins. Always.
By some distance the most expensive and most common mistake.
Measure the animal, not the box. The carrier has to let them stand, turn and lie down. Buy one "about their size" by eye and there's a good chance it's too small for the airline and too late to return the day before the flight.
Buy after measuring, not before. And check it against your airline's maximum dimensions, which are a ceiling, not a recommendation.
Break it in weeks ahead. A brand-new carrier on flight day is an unfamiliar box on an already strange day. Letting them know it in advance is the kindest thing available here, and it costs nothing.
Even with your whole history on your phone:
And one thing almost nobody does that takes thirty seconds: photograph the carrier with your dog inside before checking it in. If anything gets lost or mixed up, that photo is the fastest description you'll be able to give.
A trip is the moment you find out whether your pet's history exists outside your memory. Dates, the card, the clinic's name, the phone number on the tag — you'll be asked for all of it on the same day, in a hurry.
Today in Maskotis you can register your pet and keep their details and care events there, with dates. What's worth recording is here, and what a digital card actually is, here.
If the flight is already booked: measure your dog today. Everything else depends on that number.
Always confirm on your airline's own page before booking — these policies change, and the one at the counter is the one that counts:
Maskotis does not give medical recommendations and this article is not a substitute for a veterinary consultation. The documentary requirements described here are the airlines'; what your pet needs and when is decided by the person who can examine them. Take them to the vet you trust, or to the nearest clinic — they'll help you there.
It sounds like a step backwards and it isn't. There are four specific moments where paper wins, which is why printing is part of the product rather than an accessory.
Feature lists don't help you decide. Seven questions that do — including the three no app answers on its home page. And yes, we're one of them.
You're going to post the photo anyway. These five take exactly as long, and in three years they'll be worth far more than the photo.