Everything You Need to Know About Traveling Internationally with Your Dog
Anytime you travel with your dog on a plane, you will need a health certificate. This means if you are traveling frequently, you will be taking your dog to the vet every two weeks for a new health certificate (they're only valid for 10-14 days depending on the country).
A certificate of vaccination is also required. This is usually done at the same time of the health certificate. But, you should also make sure you have your original vaccination documents! You want to make sure you have confirmation of the dates the vaccines were administered and a vaccine card or receipts from the vaccination are best for that.
All veterinary offices that I have seen will charge you for these documents; in Peru, I pay a little under $20 USD for all of them, however I've also seen some offices in Philadelphia charged closer to $130 USD for these! I recommend you ask around for a lower price, as there is no reason to pay so much for a simple document!
 Endorsement of documents
Before you leave the USA, you will need to have your health certificate endorsed by the USDA. If not, your risking having your dog sent back to the USA upon arrival in your destination country. The original health certificate filled out and signed by your vet needs to be sent by mail (properly express since it needs to be within 14 days of travel) or hand delivered to a USDA-APHIS office. A list of endorsement offices can be found here. I was lucky enough to be driving distance from an office, made an appointment, drove up, got the signature, and drove back home (still a 3.5 hour journey in total).
Some countries require a microchip for your dog to enter. The United States does not require this, but when you leave the USA again it might be required for your destination country. Middle and Low income countries tend to be much more difficult to get accurate and updated information on this type of thing, so I recommend you just go ahead and microchip your pup to be safe! It only costs between $50-70 USD and then you never have to think about it again!
Airlines is where this can get a little tricky, as in my experience it totally depends on the people you catch on that day. This also depends a lot on if you're traveling with an emotional support/service animal or a pet. In any case, you'll need to call and let someone know you plan to travel with an animal at least two days ahead of the flight. The health certificate and certificate of vaccination are presented when you check-in for your flight at the desk.
You'll also want to consider size and space. If your dog is less than 25 pounds, they should have no issue in the cabin. However, if they are traveling as a pet they need to be within a crate of travel bag the ENTIRE flight and that carrying case needs to fit beneath the seat in front of you (about 11 inches high). This is a tight squeeze, so I hope your dog is small! If they are larger than this, you'll end up checking them as cargo in a hard-sided crate.
Some airlines require or suggest you bring a doggy air mask... when flying with your dog on other airlines, you are consenting to the fact that they don't supply oxygen masks to animals (even service animals).
 Flight times
If its your first time flying with your pup, think a little bit more about the flight times. Just like with a child, your dog is used to a certain schedule of sleeping, eating, going to the bathroom, playing, and napping. If you can align the flight with their schedule, I recommend you do it! I try to fly overnight as my dog is used to sleeping between 11 pm and 6 am and therefore is more likely to sleep throughout the flight. Her wild playtime hour of the day falls between 5 pm and 9 pm, hence I try my best to not schedule any flights during that window as I'm afraid she'll be full of energy.
If you can't do this, tire your pup out before heading to the airport! Take them for a long walk, a run, and/or to the dog park for an hour or two! The more tired your dog is, the easier they will be to manage in an airport of in a new situation.
 Taxi companies
This is something often forgotten! You'll need transportation from the airport to your hotel or Airbnb. Most public transportation options do not allow dogs or are not feasible to carry your dog onto. Uber and Cabify do not have specific rules about dogs and instead leave it up to the driver. As soon as you book your ride, call or text the driver and ask if it is OK with the dog! It is sometimes easier to just book a taxi company at the airport, in which case you can ask in-person and they can see your dog before deciding as well.
 Airbnb option
You can search Airbnb's by "pets allowed"! It definitely reduces your options, but I've found quite a lot of nice places allow small dogs! Note: I'm not sure what the policy is for support or service animals, as I've chosen to only stay at places with a pet policy in order to reduce stress.
 Doggy Daycare
Whether your traveling to a permanent destination abroad or plan to continuously travel, you'll likely need to find boarding for your dog at some point in your new country! It's much easier at home to find a family member or friend who will watch your dog, but when in a new country it's more difficult. Most veterinary offices either have a daycare option or will link you to a good one nearby. I suggest finding a vet you trust and taking their advice!
 Finding a Vet
Just like when you travel yourself and you check for closest hospitals that take your insurance, you need to check for where you would take your pup-child should they become ill or injured!
How do you find a vet in a new city? In the USA, I'd probably search reviews online and for their websites. However, in many other countries you won't find such detailed information on every vet and every office. So how do you find a trustworthy vet? Ask around! Go to the local dog parks (or areas with a lot of dogs) and ask some owners where they take their dog, as well as what is the best one in the area! People who regularly bring their dogs to a dog park are the best to ask these types of questions, as they're socializing with many other dog owners and tend to know the situation.
 Emotional Support or Service Animal
For those of us who really need/benefit from a support or service animal, this is a fantastic option. The above steps 1, 2, 4, 6, and 7 have extra tidbits.
First for your documents, you'll need a medical prescription or letter from a doctor who is actively seeing you for your condition which requires the animal. Some airlines produce forms that you can download and fill out, but I've found most will accept a long letter from your doctor with accompanying sheet of data (names, information on the dog, doctors license number, etc).
When getting your documents endorsed, bring the doctors note as well, as sometimes the APHIS office will waive the processing fee if the dog is a service animal.
You should be more free with the airlines when you have a certified support or service animal. However, some airlines do require you to present a certificate that the dog has been tested for behavior and/or is trained (in whatever service). Most airlines (if not all) will allow a support/service animal outside of a bag or crate in the plane as long as it sits within the area surrounding your seat. Some airlines will move your seat to the window seat in order to decrease any risk should their be an emergency evacuation (the thought is that the dog might block other people from getting out if they're in an aisle seat, etc.).
Depending on what country you are in, there are protective laws that will allow you to bring your service animal into taxis or hotels that do not allow "animals." By "animals," they generally mean "pets," and a service dog is not a pet.
This process is not cheap! Shop around if you have time to get a good deal! The health certificate, certificate of vaccination, vet visit, and microchip will all cost you. Hopefully you can get it all for around $125 usd. Flying with a pet will cost you as well, from what I've seen about $100 usd. Flying with a support or service animal, however, is free (for people with disabilities or need only of course). You could also be asked to pay a pet fee at hotels or in an Uber (cleaning fee), or sometimes taxi drivers say "yes if you tip".
Upon entering your destination country, you will need to pay an import fee to immigration regardless if the dog is a pet or support animal. In Peru, this fee is about $30 USD, but I don't know how this compares to other countries. There is no fee for entrance to the USA.
Have any Questions? Let me know in the comments or send me an email! I've traveled with my dog seven times and have had several issues but also have had several great experiences!