Although foot and mouth disease is one of the most highly contagious diseases known to man, it affects some animals but not humans. Although the disease itself can’t pass to humans, a large outbreak would have a devastating impact on the food, recreation and tourism economy as well as the availability of many meat and dairy products.
"Foot and mouth disease spreads primarily to animals with a cloven, or split, hoof," said Dr. Cleon Kimberling, Colorado State University Cooperative Extension veterinarian. "Those animals include sheep, pigs, cows, buffalo, deer, elk, moose, antelope, goats, mountain sheep and exotic animals such as giraffes, elephants and water buffalo. There are a few exceptions to the rule of cloven hooves; rats and hedgehogs. Humans can’t get the disease, and neither can other animals such as cats, dogs and horses. However, during an outbreak, all living and moving thing plays a role in spreading the virus that causes the disease."
When animals are exposed to the virus that causes foot and mouth disease, almost 100 percent of them get the disease. It causes blisters in their mouths and on their feet, along with other symptoms. They usually can’t eat, drink or swallow because of the blisters and loss of tissue covering the tongue and mouth. Walking becomes difficult because of lesions between the toes and around the area where the hooves connect to skin. The suffering caused by the disease runs it courses within a few months, depending on the type of animal. Young and old animals die more often from the disease than animals that were healthy when they contracted foot and mouth disease. However, almost all animals that get the disease are left with some degree of debilitation.
While the animals have symptoms, Dr. Kimberling explains, they produce copious amounts of the virus. The virus spreads to other animals – even those they don’t come into contact with because the virus can attach to almost anything and survive for some length of time. It is so highly contagious that it can spread through the wind for up to 40 miles and it can survive on clothing for several weeks. The virus also can be carried in nasal passages – even of that of a species that can’t contract the disease – and be spread through simple breathing for up to several days. In fact, Kimberling said that the virus can survive in human tonsils for up to five days.
Because animals with the disease make so much of the virus while they are sick – one pig can produce enough of the virus to infect hundreds of other animals – they are destroyed to stop the production of the virus and contain the disease to a limited number of animals. "Having to destroy that many animals is painful for ranchers and the public," said Dr. Kimberling. "But it is the best way to control the disease, prevent other animals from suffering from it, and protect the availability of food and the health of the economy for people."
If left unchecked, the disease could spread rapidly through to domestic and wild animals. If the virus was not contained, the disease would likely remain indefinitely in the United State, becoming a constant treat to wildlife and domestic animals. A foot and mouth disease epidemic in the United States would affect the production of milk, cheese and other dairy products, the availability of meat and venison, and the national and world economy.
"Foot and mouth disease has been around for centuries," said Dr. Kimberling. "Countries that are free from foot and mouth disease don’t allow imported, unprocessed food or animals from countries that are not free of the disease. For example, Europe had been free of this disease for years before this outbreak, which is believed to have been started from table scraps of meat smuggled into England from a country with foot and mouth disease."
The U. S. Department of Agriculture, along with Colorado State Cooperative Extension, the Colorado Department of Agriculture and large animal veterinarians and their associations, are actively monitoring U.S. livestock for foot and mouth disease and have plans in place to take immediate action if the disease is suspected in our animal population, said Dr. Kimberling. The USDA also has numerous regulations, protocols and precautions in place which are designed to minimize and quickly contain an outbreak of foot and mouth disease in the United States.