Sound feet and legs are important to the cow for optimal productivity, health and animal welfare (Brand et al., 1996). After infertility and mastitis, claw disorders are the third most common reason for involuntary culling of dairy cows and should be reduced (e.g. Kossaibati and Esslemont, 1997, Warnick et al., 2001; Green et al., 2002). Herdsmen usually underestimate the number of lame animals, compared with specially trained observers (Whay et al., 2002). Lesions not overtly causing lameness and/or affecting the production are often ignored (Nuss and Hassig, 2005). In spite of the fact that 60% of the Dutch farmers have their dairy cows trimmed twice a year by professional-claw trimmers (Report GD, 2006), over 70-80% of their cows had at least one disorder at the moment of trimming (Somers, 2003; Waay et al., 2004). According to Manske et al. (2002b) these figures are even higher on the farms, that don’t regularly trim the claws of their cows. This thesis should contribute to an improvement of claw health in Dutch dairy cows by further investigations into different epidemiological aspects of claw disorders in dairy cattle and an investigation into prolonged intervention in digital dermatitis.