Significant risk factors associated with digital dermatitis in Flemish dairy herds

Since more and more dairy cattle is housed in zero grazing production systems, claw health is today more than ever an area of concern. In particular, digital dermatitis (DD) or Mortellaro disease is considered a major cause of epidemic lameness. In literature, several risk factors associated with DD are mentioned. A digital survey was conducted among Flemish dairy farmers (420 completed questionnaires) to provide an overview of the prevalence of DD in Flemish dairy herds and the associated risk factors. Associations between the DD prevalence and possible risk factors are the result of a chi-squared test. A large herd with a number of lactating cows was positively associated with a high prevalence of DD (P = 0.0031). More than 67% of the respondents used a claw bath or sprayer. The use of a claw bath was positively associated with a higher prevalence of DD (P < 0.0001), however the size of the bath (length, P=0.0208 and width, P=0.0033) was negatively associated with a high prevalence of DD. The prevalence of DD was also influenced by housing type (P<0.0001) with cubicle housing being associated with a higher DD prevalence. Although a high DD prevalence (>20%) was mentioned by 34.5% of the respondents with cubicle housing, it is used in most farms (more than 85% of the respondents used cubicle housing). Cleaning of the floors by manure scrapers and robots was associated with a high prevalence of DD (P=0.0001). The DD prevalence was higher in dairy farms that buoght heifers and adult cows (prevalence DD>20% in 52.6% of the farms; P<0.0001) and in farms that already have young cattle with DD lesions (prevalence DD>20% in 51,4% of the farms; P