Why must animals with foot-and-mouth disease, or those that might have been exposed to foot-and-mouth disease, be destroyed?
Primarily for economic reasons. The disease, which causes painful, ulcerating blisters on the mouth, feet, and udders, is virulently contagious, and once introduced can quickly infect an entire herd. Though foot-and-mouth only kills about 5 percent of its animal victims, it causes rapid weight loss, miscarriage, and reduction in milk production. There is no treatment, but most animals can recover in a matter of weeks, though they are often left debilitated. Since livestock animals do not have the actuarial potential of say, a Strom Thurmond, it is not worth it to farmers to nurse back to health hogs, which are slaughtered at 6 months; or cattle, which are slaughtered after about two years. And because any country experiencing an outbreak may well be banned from the export market, total eradication is an economic necessity.
What causes foot-and-mouth disease?
An extremely persistent virus, theapthovirus, first identified in 1897, of which there are seven strains. The virus can be spread through direct contact or through the air, and can live in the environment--on clothes or hay or even in human nasal passages--for a month. Heat, chemical disinfection, or lack of moisture can kill the virus. Freezing does not.
Since it's a virus, isn't there a vaccine?
Yes, but it conveys only about six months immunity, making it very expensive to keep livestock vaccinated. Also, there are questions about whether the vaccine confers complete protection.
What animals are affected?
Cloven-hoofed livestock, such as cattle, swine, pigs, sheep, and goats; and wild animals such as deer, llama, and camels. Elephants are also susceptible. Horses, humans, and most carnivores are highly resistant.
But isn't there a human form of the disease?
It's another disease caused by another virus with a similar name. Young children in particular can contract hand, foot, and mouth disease. It causes fever, malaise, and blisters in the mouth. It usually clears up on its own within 10 days.