Vaccination requirements vary from country to country. All dogs and cats should be vaccinated against rabies before they leave the United States. Rabies may be a nonexistent threat in some areas of the world, for example, in the United Kingdom, but may become an imposing problem in some remote areas of Africa or South America. The American Veterinary Medical Association recommends that pet owners travel with a rabies vaccination certificate if they cross international borders (including travel to Canada or Mexico).
While you are abroad with your pet, it is especially important that all vaccinations and preventive medications (such as those taken to prevent infection with heartworms or other parasites) be continued.