Getting the dog's paper work from the vet was painful and expensive. I had to time it just right for our departure, but we had no other options. Dogs have to have a Rabies Certificate for the US and Mexico and a Medical Health Report for Mexico as well.
My big concern was how she would behave at the US border, so I took some peanut butter as a snack which makes it almost impossible to eat and bark at the same time. Worked really well!
Another thing to consider is that you cannot eat in restaurants, cannot go into shops together, someone always has to stay with the dog. Not such a big deal but can be inconvenient.
We crossed into the US without incident and stayed at KOA or Motel 6 without any issues. She was a great dog to have along and behaved well. She started to get a little out of sorts after the second night and seemed to take on a role of protector. She was not loud; she just seemed to stop sleeping unless we were sleeping (at night only) and would not even put her head down in the car.
When we stopped she was fearful of the loud noises made by the trucks and buses. Herman was great with this and figured that taking her off to the side and just away from any activity calmed her down. Of course at night and in the morning at the rooms we stayed in, she would eat and drink as usual and adapted well to different food, but would watch the door until we were in bed.
What we didn't know, was that we would have a difficult time to find a place to stay our first night in Tampico. No one allowed pets! We tried Best Western, Hampton Inn and Comfort Inn; two of these hotels advertise online that they do allow pets. In fact the only place that allowed a dog was an hourly motel. That's another story LMAOROF.
So far she met a few friends in Mexico who were blissfully unaware of the fact that they were off leash, and mostly when Xena approached them, they would run away. Yesterday she scared off a German Shepherd at a gas station. But we keep a close eye in case the other dogs realize that she is only 1 foot high!
Now that we are in Veracruz, taking a break at the beach in a small apartment, she is happy and her usual self. Here there are a lot of hotels who are pet friendly and we found an awesome place: Hotel Suites Mediterraneo right on the beach!