Foot-and-Mouth disease has not been a problem in the United States since 1929. But that doesn't mean the U.S. livestock industry is immune.
While it's true that the FMD outbreak in the United Kingdom has raised awareness – and concern – the fact is FMD is a constant threat. The disease periodically pops up in countries throughout the world.
One could argue that the United States is more vulnerable to FMD and other foreign animal diseases today, if for no other reason than the world's tremendous increase in international trade and travel.
Decades of FMD-free status may actually increase the United States' risk because producers and veterinarians are unfamiliar with the disease's activity and symptoms.
Still, you need to familiarize yourself with the disease as best you can. Here are answers to some frequently asked questions about FMD.
Q: What is FMD? A: FMD is a highly infectious viral disease that affects cloven-hoofed animals such as cattle, sheep, goats and pigs– including related wildlife. It does not affect horses.
There are at least seven types and many subtypes of the virus. Immunity to one does not protect against others.
Because it affects so many different animal species and because it spreads easily and rapidly, the disease presents significant concern. The economic and productivity consequences are substantial.
FMD does not affect humans. The Food Standards Agency notes the disease will not pass into the human food chain.
Q: What are the symptoms of FMD?
A: Symptoms can vary slightly between species, but there are some common signs.
- The animal's temperature spikes dramatically (especially in young animals), then falls again in about 48 hours.
- Vesicles (blisters) appear in the nose, mouth, tongue or feet (typically between the hoof line and skin). Ruptured vesicles discharge a clear or cloudy fluid, and leave raw, eroded areas.
- The animal produces sticky, foamy, stringy salvia.
- Feed consumption declines because of painful vesicles in and around the mouth.
- The animal may become lame and reluctant to move.
- Abortions in breeding stock often occur, and conception rates may decline.
- Milk flow of cows and nursing sows drops abruptly.
The disease is rarely fatal, except in very young animals. While animals typically survive, their productivity does not recover to pre-infection levels.
Q: Can FMD be confused with other diseases?
A: Yes. In swine, FMD can be confused with vesicular exanthema and vesicular stomatitis.
The only way to determine FMD from other possible diseases is to conduct a specific test. A veterinarian must collect and send blood and tissue samples to the Animal and Plant Health Inspection Service laboratories at Plum Island, N.Y. From collection to preliminary results, the process takes about 24 hours.
Q: How is FMD spread?
A: FMD can spread in any number of ways, but the virus must ultimately come in physical contact with a susceptible animal. The incubation period is 24 hours to 10 days. Animals can be contagious without exhibiting symptoms. FMD can infect an animal through the following sources:
- Animal-to-animal contact. An infected animal can begin shedding the virus within hours of exposure. The virus can remain in an animal's lymph nodes.
- The virus can survive on contaminated clothing, footwear and hair for weeks.
- Contaminated vehicles used to haul animals; the same is true for contaminated equipment.
- Raw or improperly cooked garbage containing infected meat or animal products fed to susceptible animals.
- Animals come in contact with infected premises. The virus can survive for months under the right conditions.
- Contaminated materials such as straw, hay, feed stuffs, hides or biologics.
- Infected animal semen used for artificial insemination services.
- Susceptible animals drink contaminated water.
- The virus can become airborne, although scientific details about survivability and spread are mostly unknown.
Q: What prevention and control methods are effective?
A: Because FMD exists in many parts of the world, there is always a risk that it could be introduced into the United States. Your first and best line of defense is to implement biosecurity protocols that would be effective against any disease. These include:
- Control all animal, human and vehicle traffic within your operation.
- Provide farm specific clothing and boots for everyone that comes on to the site.
- Clean and disinfect facilities between pig groups.
- Implement strict rodent, fly and bird control programs.
- Isolate, observe and test all incoming animals before entering your herd.
- Require all animal trucks and trailers, equipment and tools to be cleaned and disinfected before entering the site.
Q: What is the status of a vaccine? A: Vaccines for FMD do exist. While they reduce shedding, they do not prevent infection. No single vaccine provides universal protection against all FMDvirus types. Vaccinated animals can not be distinguished from those infected with the virus. Countries that vaccinate against FMD lose their "disease-free" status and can be shut out of export trade.
Once vaccination begins, it must become a continuous program – a costly endeavor – or the disease will resurface. Sometimes vaccines are used to limit disease spread, with the intention of culling all vaccinated animals.
Q: How long will the episode in Europe last?
A: That's a daunting question. Estimates vary greatly. A scientific adviser to the British government has said the disease could rage on for months, possibly through August.
Martin Hugh Jones, professor of epidemiology at Louisiana State University, points out that to clean up a farm it's recommended to let it sit empty for three or so months. Then the producer may bring in sentinel animals to see if they will break with FMD. If the animals remain free of the disease, serious restocking measures can begin around the seventh month following the herd depopulation.
Q: What is the United States doing to protect against FMD?
A: The United States has many steps in place to protect U.S. herds from FMD and other foreign animal diseases.
To address the current situation in the U.K. and Europe, the U.S. government has banned the importation of all animals and animal products into the United States from countries that pose a risk.
USDA, the U.S. Customs Department and APHIS have stepped up their activities as well. Customs officials are more thoroughly questioning travelers and searching baggage entering the United States from foreign countries. The Beagle Brigade – dogs used to sniff out contraband such as meat products – are in full force.
APHIS is working with federal and state health officials as well as livestock industry groups and veterinarians to keep FMD communication flowing. Also, many states are developing prevention, monitoring and control strategies in tandem with APHIS.
Q: What can you do?
A: Other than familiarizing yourself with the information here and remaining informed with activities occurring internationally and domestically, you need to keep a watchful eye on your herd.
Report any unusual or suspicious health signs to your veterinarian, state or federal animal health officials. Early detection and prompt notification are critical to limiting the spread should FMD enter the United States.
For more information about FMD contact: USDA, APHIS, Veterinary Services Emergency Programs, 4700 River Road, Unit 41, River-dale, MD 20737-8073; telephone (301) 734-8073.Check out the Web site at http://www.aphis.usda.gov.
The APHIS Emergency Operations Center is at (800) 940-6524; e-mail: firstname.lastname@example.org.
Editor's note: Information presented within this article was compiled from the National Pork Producers Council, USDA and APHIS, as well as university developed fact sheets.
For More Information
To get a perspective of the United States long-term strategy against foreign animal diseases, and some of the challenges that livestock industries face, checkout the article "It Could Happen Here" in the June 2000 issue of Pork magazine.
You also can access the article from the Pork Home Page located in the "Editorial Archive" and provide the article's title to receive a text copy.
The article also looks at classical swine fever (hog cholera) and African swine fever.