The Illnesses Your Dog Can Pick Up Abroad, and How to Prevent Them

One of the questions dog owners ask us most often before a trip is whether there is anything their dog could catch where they are going. It is a very good question, and it is the one the travel paperwork does not answer. A health certificate proves your dog is vaccinated against rabies. It says nothing about the sandflies in Andalusia, the ticks in the French countryside or the mosquitoes on the Gulf Coast, all of which carry diseases your dog has never met at home and has no defence against. The reassuring part is that nearly all of these illnesses are spread by something that bites, and something that bites can be stopped. This guide goes round the world region by region, tells you what is there and when, and ends with the short list of things to ask your vet before you leave.

Why Travel Changes the Risk

A dog that has always lived in Britain, Canada or the northern United States has usually never been exposed to the parasites of warmer places, and its owner has never needed to think about them. The danger is not that these diseases are everywhere. It is that owners do not know they exist, do nothing, and bring home a dog that seems perfectly well and falls ill months later, when nobody connects it with the holiday.

Europe's parasite specialists, ESCCAP, say to see your vet at least a month before you travel, and they publish a country by country map of what is found where. A month matters, because some protection has to be in place before the first bite. This guide is not a substitute for that conversation. Your vet knows your dog, and the right preventive depends on its age, size, breed and health, as our guide to the vet visit before you travel explains.

Southern Europe and the Mediterranean

This is where most British and northern European dogs meet trouble, because so many of us holiday there. Leishmaniosis is the one to take most seriously. It is caused by a parasite carried by sandflies, tiny biting flies that come out after sunset. According to the European vets' federation, FECAVA, it is established in Spain, Portugal, southern France, Italy, Croatia, Greece, Cyprus and Turkey. The season runs from about April to November, and all year in the warmest parts, and the disease can take anything from three months to several years to show itself.

Leishmaniosis causes skin sores, weight loss and, in the worst cases, kidney failure, and once a dog has it the infection usually stays for life. Prevention is a repellent collar or spot on treatment that your vet will prescribe, fitted before you go, and one simple habit, which is to keep your dog indoors from dusk until dawn. There is also a vaccine, which is worth discussing if you go to the Mediterranean often or for long stays.

Heartworm is spread by mosquitoes. The worms live in the arteries of the lungs and can grow to thirty centimetres. FECAVA lists Portugal, Spain, Italy and Greece as its home, and it is spreading north as the climate warms. Most dogs show nothing for months or years, by which time the damage is done. It is prevented by a regular treatment from your vet that is started for the trip and continued after you come home, so the important thing is not to stop when the holiday ends.

Tick diseases are the third group. Babesiosis, which FECAVA describes as the most important tick borne disease of dogs in Europe, destroys red blood cells and can kill quickly, and its tick is found across western, southern and central Europe as far as the Baltic. Ehrlichiosis is carried by the brown dog tick of the Mediterranean and shows itself one to four weeks after the bite. Lyme disease and anaplasmosis come from the common tick found throughout Europe, including Britain.

The defence is the same for all of them: a tick treatment that both repels and kills, started before you travel and kept up during and after, plus a daily check of your dog. ESCCAP's guideline on travelling pets makes one practical point that is easy to miss. Collars and spot on treatments can be weakened by shampooing and by a lot of swimming, which is exactly what dogs do on holiday, so ask your vet how often to renew them. Our guides to taking a dog to France and Spain explain how this fits into planning those trips.

The United States and Canada

For visitors, and for Americans driving from a cold state to a warm one, heartworm is the big one. The Companion Animal Parasite Council says dogs are at risk in all fifty states and recommends that every dog is kept on a preventive all year round. If you are bringing a dog from a country without heartworm, such as Britain, speak to your vet before you travel and not after, because prevention has to begin at the start of the trip.

Ticks are the other concern, and which disease depends on where you are. Lyme disease, ehrlichiosis, anaplasmosis and Rocky Mountain spotted fever are all present in parts of the country, and the brown dog tick is found right across it. The CDC's advice for pets is to check your dog every day, especially in and around the ears, around the eyelids, under the collar, under the front legs, between the back legs, between the toes and around the tail, and to remove any tick at once. It also warns that signs of illness may not appear for one to three weeks or longer after a bite.

In Texas and across the southern states there is also Chagas disease, spread by insects called kissing bugs. Researchers at Texas A&M say that dogs which spend a lot of time outdoors or live in kennels are most at risk, and that it can lead to serious heart problems. There is no vaccine, so the precaution is to keep your dog indoors at night in affected areas, which is when the insects feed.

Mexico, Central and South America

The newest worry here is the New World screwworm, a fly whose maggots burrow into living flesh through any open wound. The CDC issued a health advisory in January 2026 when the outbreak in Central America and Mexico reached the Mexican state bordering Texas. It is the reason a dog entering Mexico now needs an inspection certificate, and the reason you need paperwork to bring it back, as our guide to taking a dog to Mexico explains. In practical terms, look your dog over every day, treat any cut or graze seriously, and see a vet at once about a wound that is not healing.

Leishmaniosis is found across Central and South America as well as the Mediterranean, and rabies is still present in dogs in parts of the region. That is why keeping your own dog's rabies vaccination up to date matters far beyond the paperwork. Keep your dog away from street dogs, and if it is bitten, take it to a vet the same day.

Asia, Africa and the Middle East

Rabies is the dominant risk. The World Health Organization estimates that it kills around 59,000 people a year, and that dog bites cause 99% of human cases. For a travelling dog that means two things, a valid vaccination and no contact with street dogs. If your dog is bitten by another dog in a country with rabies, see a vet immediately, and if you are bitten or scratched yourself, wash the wound thoroughly and get medical care the same day.

In the tropics there is also leptospirosis, a bacterial disease spread through the urine of rats and other animals and picked up from puddles, ponds and wet ground. The Merck Veterinary Manual notes that it is found worldwide but is commonest in warm, wet climates and after heavy rain. There is a vaccine, and many dogs already have it as part of their routine jabs, so check with your vet that your dog's is current. Remember too that many countries in these regions are on the American list of high risk countries for rabies, which affects how an American dog gets home, as our guide to taking your dog abroad explains.

Australia

Australia is free of rabies and of several other diseases, which is why its entry rules are so strict. But since 2020 it has had ehrlichiosis, carried by the brown dog tick, across its northern regions. The Australian government's advice for people travelling with dogs is to get a tick treatment that repels as well as kills before heading north, to avoid places where ticks and other dogs gather, and to check your dog regularly. For Australians taking a dog on a road trip from the southern cities to the tropics, it is the same lesson as everywhere else: the risk changes with the latitude.

What to Ask Your Vet Before You Go

Take a list of everywhere you are going, including the places you will only drive through, and the dates. Then ask four things. Which parasites are found there at that time of year? What should my dog be wearing or taking, and when do we need to start? Is there anything my dog should be vaccinated against that it is not already? And what should I watch for, and for how long, after we get home?

That last question matters most, because several of these diseases hide for months. ESCCAP's guidance is that a dog returning from a leishmaniosis area should be tested at least three months after it comes home, and not straight away, because an early test can miss it. Whenever your dog is unwell in the year after a trip, tell the vet where it has been. That single sentence can save weeks of guessing.

While You Are Away

Check your dog for ticks every evening and carry a tick remover. Keep it in at night in sandfly country. Do not let it drink from puddles or stagnant water in hot climates, and keep it away from stray dogs. If you have fitted a collar or used a spot on treatment, ask your vet how swimming and bathing affect it, and top up as they advise. And if your dog does fall ill while you are away, our guide to what to do if your dog is ill or hurt on holiday explains how to find help.

A Closing Thought

None of this should put you off. Millions of dogs live long and healthy lives in every one of these places, and a visiting dog that has been properly protected is at very little risk. What catches people out is not the disease but the surprise. Spend one appointment with your vet a month before you go, put the right protection on your dog, and check it over each evening. That is all it takes to bring home the same healthy dog you left with.