A colleague in Madrid called me about a Shetland Sheepdog that had been brought into her emergency clinic by American tourists. The dog was seizing. The owners were frantic, trying to explain in broken Spanish that their dog could not have certain medications. The veterinarian, who had limited experience with MDR1, administered acepromazine to control the seizures. The dog's condition deteriorated rapidly. The acepromazine, a drug normally used for sedation, is a P-glycoprotein substrate that caused further neurological depression in this already compromised dog.
The dog survived, but the experience exposed every failure point that can occur when an MDR1-affected dog needs emergency care in a foreign country. Language barriers, unfamiliar drug names, veterinarians who have never encountered the MDR1 mutation, and owners who could not communicate critical information when it mattered most. This is a scenario that plays out more often than most people realize, and it is almost entirely preventable with proper preparation.
The Core Problem: Drug Names Change Across Borders
One of the most dangerous aspects of traveling with an MDR1-affected dog is that medications are marketed under different brand names in different countries. The ivermectin product you know as Heartgard in the United States might be sold as Cardomec in Australia, Heartgard30 Plus in Japan, or under entirely different names in South America and Asia. A veterinarian in Turkey or Brazil may not recognize the brand names you are referencing from home.
This is why knowing generic drug names, the international nonproprietary names, is essential. Ivermectin is ivermectin worldwide. Moxidectin, milbemycin, selamectin, vincristine, doxorubicin, acepromazine, and loperamide all have consistent generic names across borders. When you tell a foreign veterinarian to avoid ivermectin, they will understand regardless of what country you are in. When you say avoid Heartgard, they may have no idea what you mean.
Beyond brand names, the formulations available vary by country. In many developing nations, livestock-grade ivermectin is widely used for dogs because dedicated canine products are unavailable or unaffordable. A well-meaning veterinarian in rural Central America might reach for injectable cattle ivermectin as their standard dewormer because it is the only antiparasitic they stock. Without clear communication about your dog's sensitivity, this routine treatment could be fatal.
Preparing a Veterinary Communication Kit
Before any international trip with an MDR1-affected dog, I advise clients to prepare a communication kit. This is not a casual suggestion. It is a critical safety measure that could save your dog's life in an emergency when you cannot think clearly, do not speak the language, and need a foreign veterinarian to understand exactly what drugs to avoid.
What the Kit Should Contain
- MDR1 genetic test results with laboratory name and date of testing
- A list of prohibited drugs using generic names, organized by drug class
- A list of safe alternative drugs for common conditions including pain, sedation, parasites, and gastrointestinal issues
- Your home veterinarian's contact information with international dialing codes
- A brief letter from your veterinarian explaining MDR1 in clinical terms
- All documents translated into the primary language of your destination
- A digital copy stored on your phone and in cloud storage accessible without internet
The drug avoidance list should not just say what to avoid. It should explain why and provide alternatives. If your dog is undergoing cancer treatment, include details from our guide on chemotherapy drug adjustments for MDR1 dogs so that any emergency oncologist abroad understands the modified protocol. A foreign veterinarian treating your dog for pain needs to know not only that they cannot use butorphanol at standard doses, but that tramadol or carprofen would be appropriate alternatives. Our complete drug list for MDR1 dogs provides the foundation for building this document.
Translation Considerations
Professional medical translation is ideal but expensive. At minimum, have the drug avoidance list and the veterinary letter translated by someone with medical vocabulary in the target language. Machine translation of medical documents is risky. A mistranslation of avoid as a recommendation, or confusion between a drug name and a common word, could have consequences. I have seen machine translations that converted drug names into food items because the algorithm did not recognize them as medications.
For common travel destinations, consider preparing translations in multiple languages. A trip through Western Europe might require documents in French, German, Italian, and Spanish. A journey through Southeast Asia might need Thai, Vietnamese, and Indonesian translations.
Country-Specific Concerns
Different regions present different challenges for MDR1-affected dogs. Understanding these before you travel allows you to prepare specifically for the risks you will encounter.
Europe
Western European veterinarians are generally well-informed about MDR1, particularly in countries with large herding breed populations like the United Kingdom, Germany, France, and the Netherlands. The mutation was first characterized in research partly involving European Collie populations, and awareness among veterinary professionals is relatively high.
However, entry requirements for many European countries include mandatory parasite treatments. The UK requires dogs to be treated with praziquantel for tapeworms within specific timeframes before entry. Some countries have historically required broader antiparasitic treatment. Check current requirements well in advance, and work with your veterinarian to ensure the required treatments use MDR1-safe drugs.
Central and South America
Veterinary practices in much of Central and South America routinely use livestock-grade antiparasitics for companion animals. Ivermectin is widely available and inexpensive, making it the default choice for many practitioners. Access to dedicated canine antiparasitic products varies significantly by region and economic factors.
If your dog needs parasite treatment while traveling in these regions, bring your own MDR1-safe products from home. The newer isoxazoline-class products like NexGard and Bravecto are particularly convenient for travel since they are safe for MDR1 dogs and provide reliable flea and tick protection regardless of what local veterinarians have in stock. Do not rely on finding appropriate alternatives locally, especially outside major cities.
Asia and the Pacific
Awareness of the MDR1 mutation is growing in Japan, South Korea, and Australia, all countries with significant herding breed populations. In Southeast Asia, awareness is much lower, and veterinary infrastructure in rural areas may be limited.
Australia deserves specific mention because of its strict biosecurity requirements. Dogs entering Australia typically undergo extended quarantine and may receive multiple antiparasitic treatments during the quarantine period. You must communicate your dog's MDR1 status to the quarantine facility before arrival and provide documentation supporting the use of alternative drugs.
Africa and the Middle East
In many African countries, ivermectin is the most commonly available antiparasitic for both livestock and companion animals. MDR1 awareness is generally low among veterinary practitioners. Bring a complete supply of safe antiparasitic products and carry detailed documentation explaining the genetic condition and drug avoidance requirements.
Emergency Preparedness Abroad
The nightmare scenario is your MDR1-affected dog having a medical emergency in a foreign country where you do not speak the language and the nearest veterinarian has never heard of MDR1. Here is how to prepare for that possibility.
Before departure, research veterinary emergency facilities at your destination. Many international cities have 24-hour veterinary clinics staffed by English-speaking veterinarians. Save their addresses and phone numbers in your phone. If traveling to remote areas, identify the nearest veterinary facility along your route even if it is hours away.
Consider pet travel insurance that covers emergency veterinary care internationally. Verify that the policy does not exclude pre-existing conditions, as some insurers might classify MDR1 as a pre-existing genetic condition. Read the fine print about coverage limits and repatriation.
Carry a basic emergency kit that includes your dog's current medications, anti-nausea medication if your veterinarian prescribes one for travel, and a muzzle for safe handling if your dog is in pain. Our first aid guide for ivermectin exposure provides protocols that apply regardless of where you are in the world.
Emergency Card Template
Carry a card in your wallet or on your phone with this information, translated into the local language:
Line 1: This dog has MDR1 gene mutation (multidrug resistance gene deficiency).
Line 2: DO NOT administer: ivermectin (high dose), acepromazine, butorphanol, loperamide, vincristine, or other P-glycoprotein substrate drugs at standard doses.
Line 3: SAFE alternatives for sedation: midazolam, propofol. For pain: carprofen, meloxicam. For parasites: fenbendazole, pyrantel, praziquantel.
Line 4: Contact my veterinarian: [name, phone with country code].
Mandatory Treatments and Border Crossings
Several countries require specific antiparasitic treatments before or upon entry. These requirements exist to protect domestic animal and wildlife populations from imported diseases and parasites. They are non-negotiable, but the specific drug used can sometimes be modified.
Start this process months before your trip. Contact the destination country's agricultural or veterinary import authority. Explain your dog's MDR1 status and ask whether alternative medications are accepted. Get any agreements in writing. Many border officials will only accept documentation from their own country's authorities, not a letter from your home veterinarian.
Some countries require ivermectin-based treatments specifically. In these cases, remember that low-dose ivermectin at heartworm prevention levels is generally safe even for MDR1 homozygous dogs. The problem is not all ivermectin. It is high-dose ivermectin and certain other P-glycoprotein substrates. Work with your veterinarian to determine whether the required treatment dose is within the safe range for your dog's specific MDR1 status.
Communicating With Foreign Veterinarians
Effective communication with a foreign veterinarian goes beyond handing over a translated document. Here are practical strategies I have developed after consulting on numerous international cases.
Use the term "MDR1" universally. It is the same abbreviation worldwide and most veterinarians with any pharmacology training will recognize it. If that does not register, try "P-glycoprotein deficiency," which is the functional description and is understood in the scientific community globally.
If language is a complete barrier, show photographs on your phone of the genetic test results, the drug list, and the veterinary letter. Visual documentation communicates across languages better than spoken words. The real-world stories shared by owners who have dealt with drug reactions, such as those documented at Collie Drug Reactions, can also help convey the seriousness of the condition when words fail.
Ask the veterinarian to confirm each medication before administering it by writing down the generic drug name. If you cannot verify that a proposed drug is safe, err on the side of refusal. It is better to delay non-emergency treatment until you can confirm drug safety than to risk a potentially fatal reaction.
Bringing Medications Across Borders
Carrying your dog's medications internationally introduces another layer of complexity. Controlled substances, including some sedatives and pain medications, may be restricted or prohibited in certain countries. Even non-controlled veterinary medications may require import permits or veterinary prescriptions from the destination country.
Carry all medications in their original labeled containers with the prescribing veterinarian's information visible. Bring a letter from your veterinarian on clinic letterhead explaining each medication, the reason it is prescribed, and the dosage. This letter should specifically mention that these medications are required because standard alternatives are contraindicated due to a genetic condition.
Research the specific regulations for each country on your itinerary. Some countries that restrict certain medications when imported by individuals allow them when accompanied by veterinary documentation. Others require advance import permits that must be applied for weeks or months before travel.
Coming Home
Re-entry into your home country may also involve antiparasitic treatments, particularly if you have been traveling in regions with exotic parasites. The United States currently does not require antiparasitic treatment for returning dogs, but the rules around dog importation have been tightening and may change. Check current requirements before your return trip.
After returning home, schedule a veterinary check-up that includes screening for parasites common to your travel destinations. Some foreign parasites require specific treatments that may need MDR1 consideration. Having your regular veterinarian handle this, with full knowledge of your dog's drug sensitivities, is much safer than dealing with it abroad.
The Bottom Line for Traveling Owners
Traveling internationally with an MDR1-affected dog is absolutely possible, but it demands preparation that goes well beyond the standard pet travel checklist. Document everything. Translate everything. Research your destinations. Identify emergency resources. Carry your own medications when legally possible. And never assume that a foreign veterinarian knows about MDR1, even in countries with sophisticated veterinary systems.
The twenty minutes you spend preparing a veterinary communication kit could save your dog's life in a foreign emergency room. The hour you spend researching veterinary clinics at your destination could mean the difference between reaching a facility that understands your dog's needs and ending up somewhere that has never encountered the mutation. Preparation is not paranoia. For MDR1-affected dogs, it is essential care.