Foot-and-mouth disease is a highly contagious viral disease of cattle, sheep, hogs, and other animals with cloven (divided) hoofs. It is also known as hoof-and-mouth disease. The infection does not actually affect the hard structures of the hoof, but rather the soft tissues around it. Foot-and-mouth disease occurs among livestock in many regions of the world, particularly in Africa, Asia, and South America. The disease is rare in Australia, much of Europe, and North America.
Cause and symptoms.
A small, ball-shaped virus causes foot-and-mouth disease. Healthy livestock may acquire the disease through contact with infected animals or with objects that have been contaminated by saliva, other body fluids, or wastes from infected animals. Winds and animals that are not themselves affected by foot-and-mouth-disease, such as birds, cats, and rats, may spread the virus. People may also spread it if they have been in direct contact with the virus. It is possible for people to develop a mild, temporary infection.
The virus produces painful, fluid-filled blisters on the lips, tongue, gums, nostrils, and upper part of the foot. In animals, blisters also develop in the tissue between the two parts of the hoof. The blisters break open after a few days and become raw sores. Infected animals also develop a high fever, salivate (drool) excessively, have difficulty walking, and lose weight. In female animals, the virus also affects the milk-producing glands, decreasing their yield. Foot-and-mouth disease rarely kills adult animals, but it causes a higher death rate among the young. The disease hurts farmers economically by reducing their livestock’s meat and milk production.
Control.
There are no specific cures or treatments for foot-and-mouth disease, but farmers use a variety of methods to control or prevent it. In the African, Asian, and South American countries where the disease is endemic (found regularly), livestock owners control it chiefly through the use of vaccines. Veterinarians must administer vaccines at regular intervals because most vaccines protect the animals for only a short period. The vaccines are also expensive, and in some cases, they accidentally contain live viruses that may infect the animals.
In the United States and most other countries where the disease is not endemic, it is controlled chiefly through import restrictions and quarantine procedures. Such measures normally prevent the introduction of the virus. These countries also have policies for eliminating the virus if an outbreak occurs. Most such policies call for slaughtering the infected animals, burying or burning their carcasses, and decontaminating the area where the animals lived. In 2001, a rare outbreak of foot-and-mouth disease in Europe led to the slaughter of hundreds of thousands of cattle, sheep, and pigs. Imports of meat from Europe were banned in the United States and other countries in an attempt to control the spread of the disease.
