An observational study on managing digital dermatitis through risk assessment and veterinary advice on 19 Dutch dairy herds

Objectives

First, identify associations between digital dermatitis (DD) prevalence and a DD risk score. Second, determine the effect of veterinary advice based on the risk score on DD prevalence and management by farmers and their veterinarians.

Material and methods

Nineteen farms with routine veterinary herd health visits from one veterinary practice were visited between March and April in 2016 and 2018. Selection criteria were (1) presence of DD, (2) milking parlor suitable for in-parlor M-scoring and (3) willingness to participate in the study. During the farm visit, DD prevalence was determined and a DD risk assessment (RA) survey done. At the end of the visit, farmers were given a list of cows with M2-lesions, eligible for treatment. The DD RA survey was an interim version of the lameness RA questionnaire (University of Calgary). It consisted of 22 MCQ with sections on foot health, housing and general management. Each answer was given a risk score based on published literature, with higher scores indicating higher risk for DD. Risk scores of all questions summed up to a total risk score (TRS). Two veterinary students, one in 2016 and one in 2018, performed the farm visits and were trained in M- and leg hygiene scoring using published literature, classroom training with digital color photographs and in-parlor scoring of washed hind feet of around 50 dairy cattle using a mirror glued on a spatula and a powerful headlight. Dairy herd improvement data were extracted from farm management software with consent. [...]