Can We Prevent Hoof Problems? Roger Blowey Wood Veterinary Group, St Oswalds Road, Gloucester, GL2 8JG, UK Email: rblowey@gloucs-vet.demon.uk Take Home Message Lameness remains a major problem in dairy cattle worldwide. In the UK the average incidence is around 50 cases per 100 cows per year, with much higher incidences being seen in some free-stall housed cattle. Because of its effect on subsequent fertility and production, the cost of a single case of lameness is estimated to be around £200 ($450 Canadian), although this will vary enormously from case to case depending on severity. The prevention of any disease must be based on a thorough understanding of its cause, and the following points are discussed in this paper: 8 the structure of the foot, viz. hoof, corium and bone 8 how dysfunction of the corium (‘coriosis’) leads to the production of defective hoof horn 8 when the defective horn reaches the weight bearing surface of the foot, lesions causing lameness may develop 8 calving is a major cause of coriosis, which is why peak incidence of lameness is seen 2 to 4 months into lactation. Hoof growth stops but wear increases. This leads to a thinning of the sole, which in itself predisposes to further bruising and coriosis 8 many of the other on-farm factors that predispose to coriosis also occur at the time of calving, and include feeding, excess standing and changes in housing and management. The Structure of the Foot The foot consists of two digits, the outer or lateral claw and the inner or medial claw. In hind feet the outer claw is larger than the inner and is the major weight-bearing surface. In front feet this is reversed, with the inner claw being the larger and weight-bearing. This is thought to be an important reason why Advances in Dairy Technology (2002) Volume 14, page 83