One of the countries I was going to be in for a good while-- England -- required the quarantine. I forget how Italy was. But once over there, they treat dogs much better than we do here. You can take them in the restaurants on leash -- I saw dogs in every type of restaurant, ordinary diner types and 4-stars. You can also take pets on the train, which is a convenient way to travel.
I would check with AAA, if you belong, or the Dept. of State.
If I could have avoided England, I would have and then just gone
to the countries that accepted pets. Germany was one I recall.
Of course, you need to show a health certificate and all current
shots. I have never been to Mexico, but I have been to Canada and it is
pretty simple, just show the current health certificate. Good luck and have fun.
Rebecca