If one looks at PQ 2164 Peter Ainsworth and the PA, it soon becomes clear that there was unnecessary slaughter in Northumberland.
Briefly, of 85 clinically diagnosed IPs, 75 were tested but 58 only had the disease.
There were 12 SOS, all of which were tested and none of which had the disease. A further 313 DCs to the 85 IPs were taken out, of which 201 were contiguous premises. (What were the other 112 DCs? Locals say that there was a 3 km cull).
Of these 313 DCs, only 22 were tested but none had the disease.
Statistically, disease would have shown up in the 22 if indeed there was the infection claimed by the modellers.