Two cows have been killed by the highly infectious but rare disease anthrax in the first outbreak in Britain for four years.

The cases were on a beef farm in south Wales. Several tests have been carried out on the farm after the sudden deaths of five cows, but these are the first to produce positive confirmation of the bacteria in blood samples.

The carcasses of the cows have been burnt on site with ashes disposed of in secure conditions, in accordance with the Anthrax Order 1991, and staff working at the incineration sites have been advised of health and safety procedures.

All unexplained sudden deaths of cattle are investigated for anthrax, and hundreds of samples are examined each year.

In this case the carcasses were tested as a matter of routine, although anthrax was confirmed on the same farm 35 years ago.

Anthrax spores can persist for many years in the environment and investigations are being carried out to see if the current outbreak is related to the previous one.

No cattle on the affected farm have entered the food chain for almost a year.

Anthrax is a rapid disease and an animal suffering it would not be sent for slaughter because it would be obviously ill. Ante-mortem checks by the Meat Hygiene Service provide an additional safeguard.