The most economically damaging fact about foot-and-mouth disease is that cattle infected with FMD and cattle vaccinated for the disease, when tested, appear practically the same. That means the many healthy animals, oftentimes, have to be culled to make sure the outbreak is stopped.

German researchers have created a cheap test that reportedly distinguishes between those with the disease and those vaccinated.  That would allow future outbreaks to be stopped through immunization rather than culling.

The fast, low-tech lab test reliably sorts the two groups, say Armin Saalmüller and colleagues at the Institute for Immunology of the Federal Research Centre for Virus Diseases of Animals in Tübingen, Germany.

"It could easily be made into a strip test - like a dipstick," FMD expert David Paton of the Institute for Animal Health in Pirbright, United Kingdom, told Nature magazine. Animals could then be checked in the field.

Critics of the test say it isn’t sensitive enough to the disease.

"It's possible that you'd be using this test on millions of animals," said FMD epidemiologist Mark Woolhouse of the University of Edinburgh, United Kingdom. "No diagnostic test is perfect," he said.