Panic in the Barnyard!

The most severe animal epidemic in decades has ravaged Western Europe --and health experts fear it could reach U.S. shores. Foot-and-mouth disease (FMD) attacks cloven-hoofed animals like cows, pigs, and sheep, and is triggered by a virus (microscopic agent that causes disease). "It spreads like wildfire," says Sandy Hays at the Plum Island Animal Disease Center in New York.

What's being done to thwart the spread of FMD? Mass slaughter. And since last February, more than 1 million farm animals across the UK, Ireland, France, and the Netherlands have been slaughtered and burned or buried. Some health officials have resorted to emergency vaccinations (injections that trigger the immune system to fight disease), which has sparked controversy across Europe: vaccinated animals can still carry the disease, and vets can't easily tell vaccinated animals from infected ones.

British officials now suspect that pigs at a single farm in northeastern England first fell victim to FMD, the UK's only outbreak since 1967. The virulent virus strain of the recent plague is called type O, strain Pan-Asia (one of seven FMD virus strains). It infects an animal's epithelial cells--tightly packed cells that line the nose, mouth, blood vessels, and most organs. The painful result: blisters that erupt on the mouth, tongue, nostrils, and hooves. "FMD affects the foot to the point that nails come off, making it difficult to stand," says veterinarian Joe Annelli at the United States Department of Agriculture.

FMD spreads by direct or indirect contact with infected animals, which shed the virus in their saliva, tears, blood, semen, urine, and feces. The virus can linger for weeks in feed, hay, manure, and dust, and can even spread via shoe soles, car tire treads, or mere gusts of wind. Alarmed British officials have imposed travel restrictions, suspended sporting events--even canceled St. Patrick's Day parades last March.

Experts foresee no quick end to the epidemic--and predict 3.6 million European farm animals will be slaughtered by June. In turn, the U.S. government acted swiftly, banning imports of all livestock, fresh meat, and some dairy products from the 15 nations that compose the European Union. The good news? Unlike mad cow, disease, another viral illness wreaking havoc in Europe, people don't catch FMD. "Unless you have a cloven hoof," says Hays, "you're not going to get this."

* Watch for our feature on mad cow disease next fall.

Two easily confused diseases

MAD COW DISEASE

Infects cows; related diseases attack sheep, humans

Suspected cause: Disease-carrying proteins called prions or heat-resistant virus particles.

1 Person animal eats food contaminated with brain or spinal cord tissue from an infected animal.

2 Disease attacks nervous system.

Severity: Can kill livestock and humans; "mad" seizures may begin months or years after infection.

Prevention: Destroy infected farm animals; don't use animal products containing brain or central nervous system tissue as livestock feed.

FOOT-AND-MOUTH DISEASE

Infects only "cloven-hoofed" animals (cattle, sheep, goats, pigs, etc.)

1 Animal touches or ingests virus.

2 Animal becomes sick.

3 Virus spreads easily to other animals.

Severity: Causes mild or severe illness; animals that survive produce less meat, milk than usual.

Prevention: Stop spread of virus by isolating, destroying infected farm animals; disinfect objects that may be contaminated.