An intervention trial by Hedges and others (2001) studying 1109 cow-years, in which every lame cow was examined and recorded by a veterinary surgeon, determined the four main causes of lameness to be sole ulcers, white line disease, digital dermatitis and interdigital necrobacillosis (‘foul’ or ‘foot rot’) (see graph on the right). Sole ulcers and white line disease are defects of the hoof and,...