What is bovine tuberculosis?

This is the name given to the type of tuberculosis that infects cattle.

The disease damages the animal's lungs and eventually leads to death.

There are very few clinical signs of the disease but most animals will develop lumps on their body, usually on the flanks.

Unlike foot-and-mouth disease TB is usually only caught by a handful of cattle rather than a whole herd.

How many cattle have died as a result of TB?

The disease was at its worst in the 1930s when large numbers of dairy cows were affected.

Due to testing and the slaughter of animals thought to be infected the numbers were reduced but the risk to cattle remained.

In recent years the numbers of cattle dying from TB have been slowly rising. In 1999 a total of 7,000 cattle died rising to 8,000 in the year 2000.

How does it spread?

There are thought to be various way the disease can be spread - possibly directly from one animal to another or alternatively through an outside source, such as badgers.

In November 1996 Professor John Krebs and the Independent Review Team began a scientific review on behalf of the government into the link between bovine tuberculosis and badgers.

The review concluded that the evidence that badgers were a significant source of tuberculosis infection in cattle was compelling.

But it was unable to say exactly how much of the disease originated through badgers due to a lack of data, or how effective badger culling would be as a means of eliminating TB.

As a result 10 trials were introduced to research the causes of bovine TB. These include controversial badger culling trials. The results of this research is not expected to be available until 2005-6.

What is the government doing to control the problem?

As well as the 10 trials, the government is carrying out routine testing for TB on cattle.

Animals found to have the disease are slaughtered and movement restrictions are imposed on the individual farms for a period of up to six months.

Could the outbreak be as bad as the foot-and-mouth crisis?

Officials from the Department for the Environment, Food and Rural Affairs are optimistic that in March and April this year there will be a slowdown in the disease.

But the commercial impact of TB on a farmer - mainly through movement restrictions - is thought to be as bad, if not worse, than having a case of foot-and-mouth.

Can the disease spread to humans?

Bovine TB can be passed on to humans but instances of this happening are very rare, mainly due to the introduction of pasteurised milk.

Scientists recently made a breakthrough which has brought them closer to finding a vaccine for bovine TB, which they believe could also be used to treat humans with the disease.