Taking Your Dog From the US to Mexico, and Bringing It Home

For years, taking a dog to Mexico was almost as simple as taking one to Canada. That has changed. An outbreak of a parasite called the New World screwworm has reached Mexico, and both countries have brought in new rules because of it. A trip that used to need nothing now needs a vet visit before you go and another before you come home. It is still very manageable, but only if you know about both appointments, and many people learn about the second one at the border on the way back. This guide sets out the whole journey, using the rules as the American authorities stated them in early October 2026.

The Trip in Brief

Before you enter Mexico, an accredited vet must inspect your dog and sign a screwworm inspection certificate, no more than five days before you cross. Before you come back to the United States, an authorised vet in Mexico must inspect your dog and certify it free of screwworm, again within five days of your return. You also need the CDC Dog Import Form to re enter, and your dog must be at least six months old and microchipped. The rules came in quickly and may change again as the outbreak develops, so read the official pages once more in the week before you travel.

What Screwworm Is

The New World screwworm is a fly whose maggots feed on living flesh. The fly lays its eggs in any open wound, even a small scratch or a tick bite, and the maggots burrow in and enlarge it. Left untreated, an infestation is painful and can kill. The parasite was eradicated from the United States in the last century, and the authorities on both sides of the border are now working to contain it, which is why a pet dog is inspected in both directions.

The inspection itself is nothing to worry about. A vet looks your dog over carefully for wounds and for any sign of the maggots, and signs a form to say there are none. The risk to a well cared for pet on a short holiday is small. But it explains why the rules are strict about wounds, and why the most useful thing you can do before the trip is make sure your dog has no cuts, sores or hot spots.

Going Into Mexico

Since 3 August 2026, according to the USDA's guidance for travel to Mexico, a dog entering Mexico from the United States must have a screwworm inspection certificate signed by a USDA accredited vet and issued no more than five days before it enters. The department publishes the form on that page. It does not have to be sent to the department for endorsement, which keeps the process quick and means the certificate can be done in a single visit.

Not every vet is accredited, so ask when you ring to book, and time the appointment with care. Five days is a short window. If you are driving for two days to reach the border, those two days come out of the five, and a delay on the road can leave you with a certificate that has run out. Book the appointment for two or three days before you expect to cross, not five.

On arrival, your dog is inspected by Mexico's agricultural health service, SENASICA, at its office in the airport or at the border crossing. The inspector checks that the dog shows no signs of disease, has no parasites and has no fresh wounds. Bring the dog in a clean carrier or crate without bedding, toys or loose food, apart from the ration for the day, because those things can be taken away. So check your dog over yourself beforehand, treat it for fleas and ticks in good time, and if it has a cut or a sore, have it seen and healed before the trip.

While You Are There

The parasite that caused all this is the main thing to watch for during your stay. Look your dog over every day, running your hands over its coat and checking between the toes and under the collar. Clean and cover any cut, however small, and have a vet look at any wound that is not healing or that your dog keeps licking. Keep its flea and tick treatment up to date, since a tick bite is one of the ways a wound begins. Our guide to the illnesses dogs can pick up abroad covers screwworm and the other risks of the region.

Heat is the other concern. Much of Mexico is hot for most of the year, and the beach resorts are the hottest of all. Walk early and late, keep the dog in shade or air conditioning through the middle of the day, and carry water wherever you go. Hot sand and pavement burn paws, so test the ground with the back of your hand. Our guide to heat and your dog on holiday explains how to plan a hot day and how to recognise heatstroke.

Keep your dog away from street dogs, which may carry disease and are not always friendly, and do not let it drink from puddles or standing water. Before you travel, find a vet near where you are staying and save the address and number in your phone. You will need one for the certificate to get home in any case, and if your dog falls ill, you will be very glad not to be searching in a hurry. Our guide to what to do if your dog is ill or hurt on holiday explains how to find help in a place you do not know.

Coming Home

There are two requirements for the return, and they come from two different agencies. The first is the screwworm certificate. The USDA states that a dog coming from a country where screwworm exists may enter the United States only if it has a certificate saying it was inspected for screwworm within five days before travel and found free of it. This applies to American dogs returning home, not only to dogs from Mexico.

Normally such a certificate must be signed by a government vet. For Mexico, the department accepts one from a private vet who has been trained and authorised to sign on the government's behalf, and its page links to Mexico's directory of those vets. There is no set form, and the certification can stand alone or be part of a health certificate. Your papers are reviewed and your dog is inspected at the port of entry. So find an authorised vet near where you are staying before you leave home, and book the appointment for the last few days of your trip.

The second requirement is the CDC Dog Import Form, which is needed for every dog entering the United States. You complete it online and show the receipt at the border or to your airline. The dog must be at least six months old and have a microchip that can be scanned. Mexico is not on the CDC's list of countries at high risk for dog rabies, so the form is all the CDC asks for, and you can complete it before you leave home.

Driving or Flying

Driving across is common, and the process is the same as by air, with the SENASICA inspection on the way in and inspection by American officers on the way back. Allow extra time at the border in both directions, and cross at a main crossing during normal working hours, when the inspection office is most likely to be staffed. Keep the dog secured and cool in the car while you wait, because queues at the border can be long and hot. Our guide to driving with your dog has more on long journeys by road.

If you fly, check your airline's rules for Mexico before you book. The big American airlines take small dogs in the cabin on Mexican routes and will ask to see the screwworm certificate at check in, while Frontier and Southwest do not carry pets on international flights at all. Avoid putting a dog in the hold on a flight to or from a hot airport in summer. Our guide to flying with a dog compares the airlines and their fees.

A Timeline

A month before you go, check the rabies vaccination and the microchip, find an accredited vet at home and an authorised vet in Mexico, and treat your dog for parasites. Within five days before you cross, get the screwworm inspection certificate from your accredited vet, and complete the CDC Dog Import Form before you leave home. On arrival comes the SENASICA inspection. Within five days before you return, get the screwworm certificate from the authorised vet in Mexico. At the border, have both documents in your hand.

A Closing Thought

The rules for Mexico are new and they arrived quickly, but the logic behind them is simple. Each country wants a vet to look at your dog shortly before it crosses. Book both appointments before you leave home, keep your dog free of cuts and parasites, and the border becomes a short wait and a quick look, which is a small price for a winter in the sun with your dog beside you.