Hundreds of farms may have been wrongly diagnosed as harbouring the foot and mouth (FMD) virus, leading to the unnecessary slaughter of thousands of animals, according to the latest admission from the Ministry of Agriculture, Fisheries and Food (MAFF).  Senior vets from the laboratory in Surrey, which carried out tests on animals slaughtered due to confirmed infection by the virus, have revealed to Channel Four News that around 30% of the animals were not infected after all. This means that only 46 of the 250 farms where animals were slaughtered on suspicion of having the disease were actually confirmed as positive by tests. Also, 450 of the 1,579 farms so far confirmed to have the virus have now been proved negative.