Animal health officials in Texas are watching with concern the relentless westward march of foot-and-mouth disease (FMD), the most recent outbreak of which was confirmed in late February at several sites in England, where livestock operations already have been financially ravaged by the brain-wasting disease, BSE (bovine spongiform encephalopathy) and outbreaks of the viral infection, hog cholera.

Additional cases of FMD have been detected among cattle, sheep and swine in Great Britain (encompassing England, Wales and Scotland). In addition to the loss of thousands of animals, British farmers may lose as much as $73 million just from the week-long ban (which could be extended) on the transport and marketing of livestock susceptible to the disease.

FMD, which has not been seen in the U.S. since l929, is caused by a highly infectious virus that can cause death or disabling blisters and sores in and around the mouth, muzzle, teats and feet of livestock with cloven or "split" hooves.

Cattle, pigs, sheep, goats and deer are highly susceptible, and can exhibit clinical disease signs after an incubation period of only three to eight days. To stop the spread of infection, affected or exposed animals must be slaughtered, then burned or buried. Premises and equipment must be disinfected to prevent disease spread.

For a map showing FMD outbreaks worldwide, click here.