A:

One reason is that the scope of equine travel has shown staggering growth in recent years. International travel is the most important factor when it comes to the global spread of infectious disease. In 1997, 517 international equine events were recorded. This number increased to more than 3,400 by 2016. Widespread outbreaks are becoming all too common among these equine travelers.

Even if your horse isn’t an international traveler, global increase in horse movement still puts him at increased risk for exposure to disease. Officials are working hard to develop systems to minimize these risks.

Another risk factor: The United States horse population is one of the most naïve populations in the world when it comes to many foreign diseases. An example is equine piroplasmosis, a tick-borne disease