Cattlemen Issue Primer on Disease

March 21, 2001

The National Cattlemen's Beef Association has issued what amounts to a primer on foot and mouth disease as well as bovine spongiform encephalopathy (BSE) or mad cow disease. Although there have been no reported cases of either in the United States, outbreaks of both in Europe have U.S. livestock producers and processors on edge. F&MD does not affect humans but can cause whole herds to be destroyed, as is taking place in Europe now. Humans are susceptible to a form of BSE, however.

NCBA says a major reason the United States has remained free is because of aggressive prevention measures designed to protect U.S. cattle herds and assure the safety of the beef supply for American consumers. The association issued a list of prevention measures for both F&MD and BSE.

F&MD is a highly contagious viral disease that does not affect humans but has devastating effects on animals with cloven hooves, such as cattle, swine, sheep, goats and deer. The United States has not had a case of foot-and-mouth disease since 1929, an outbreak that was quickly contained and eradicated.

There are seven types of the F&MD virus, all of which have similar symptoms. Immunity to one type does not protect animals from other types. The average incubation period is between three and eight days, but can be up to two weeks in some cases. The disease is rarely fatal but may kill very young animals. Animals that survive are often debilitated and experience severe loss in milk or meat production.

Foot-and-mouth disease is a highly contagious virus and can be spread by movement of infected animals, movement of contaminated vehicles, and by contaminated facilities used to hold animals. It also can infect animals through contaminated hay or feedstuffs and if susceptible animals drink from a common water source. While FMD is not considered a threat to human health, people who come in contact with the virus can spread it to animals through clothing, footwear or other equipment/materials. The virus can harbor in the human nasal passages for as long as 28 hours. Wind also can spread the virus through the air.

If FMD were to occur in the U.S., the degree of economic impact would depend on how quickly the disease was identified and effective control measures put in place. If it was controlled quickly and eradicated, as was the case with the last outbreak in the U.S. in 1929, the damage might be small. However, if the disease became widespread, the economic loss could easily be many billions of dollars.

The most serious effects would result from the necessity of destroying animals in order to eradicate the disease. In addition, countries with F&MD experience restricted exports.

First diagnosed in 1986, BSE is a degenerative disease affecting the central nervous system of cattle. Commonly known as "mad cow disease," BSE has not been found in the United States, but it has been detected in the United Kingdom and other European countries. Research from the U.K. indicates the BSE disease agent has been found in brain tissue, the spinal cord and retina (eye) tissue of naturally infected cattle. It has not been detected in muscle meat or milk.

A surveillance program begun in 1990 by USDA has found no evidence of BSE in U.S. cattle. In addition, USDA, the Food and Drug Administration (FDA) and many arms of the U.S. livestock industry have taken a number of measures for more than a decade to prevent BSE from occurring in the U.S.

The United States was the first country in the world to implement stringent feed and import bans without having BSE within its borders. No beef has been imported from the U.K. since 1985. In 1989, the U.S. banned the importation of ruminant animals (cattle, sheep, goats, deer, elk and buffalo) and at-risk ruminant products (such as meat and bone meal) from all countries where BSE had been found.

In 1997, the USDA banned imports of all live ruminant animals and at-risk products from all European countries. Also in 1997, the FDA banned the feeding of most mammal-derived protein supplements to cattle and other ruminants because, in Europe, the disease spread through feed containing protein supplements that carried the BSE disease agent. The feed ban is a critical firewall measure and is an extra precaution against BSE. While BSE has not been found in the U.S., the feed ban assures that if BSE somehow ever did get into this country, it would be quickly isolated and eradicated.

While the 1997 ban is a critical firewall measure, it should be noted that just feeding mammal-derived proteins to cattle does not cause BSE in and of itself. BSE is only spread by feed if that feed is contaminated with the disease agent. USDA also continues to take stringent measures. In December 2000, it banned imports of all rendered animal protein products, regardless of species, from all European countries.