But animals that can actually contract the disease, such as cattle, sheep, hogs and goats, most often are destroyed if they've been exposed to it. So, if the virus surfaces in any country, region or state, it's impossible to legally sell, breed, show or export the exposed animals anywhere. Usually, the only economically viable option becomes to kill the livestock. So while the disease normally only kills young animals, it wreaks havoc on the entire herd. But there is a vaccine that, while not 100 percent effective, can prevent symptoms.
Trouble is, it creates the same bloodstream markers, called titers, as the disease itself.
There's no way to tell if the animal has just been inoculated or really has the illness. Even if livestock are vaccinated, they're usually slaughtered anyway, to eliminate any chance they'll spread the virus. But its development will take years. However, there may be another way to employ existing vaccines. The USDA should work with its international counterparts to develop methods of tracking which animals have been vaccinated.