Spatial patterns of recorded mastitis incidence and somatic cell counts in Swedish dairy cows: implications for surveillance

Abstract

Abstract. Clinical mastitis (CM) is the most common veterinary treated disease in Swedish dairy cattle. To investigate if the distribution of veterinary registered cases of CM in Sweden follows that of the spatial distribution of cows with high somatic cell counts (SCCs), the spatial distribution of CM odds was estimated from available records and compared with udder health measures based on measurements of SCC derived from official milk recording. The study revealed areas with significantly lower odds for CM but with a high proportion of cows with a poor udder health score, suggesting an under-reporting of CM. We also found areas of significantly higher odds for CM despite a low proportion of cows with a poor udder health score, suggestive of over-treatment of mastitis. The results should enable targeted studies of reasons for discrepancies, e.g. farmers' and veterinarians' attitudes to mastitis treatment and disease recording in areas with a deficit or excess of registered CM cases. High quality disease records for dairy cattle are of interest not only for the dairy management but also for disease surveillance, monitoring of use of antibiotics and food safety purposes.

Data quality in the Norwegian dairy herd recording system: Agreement between the national database and disease recording on farm

“…Investigating and describing data quality in animal disease databases have been carried out in different ways and using varying terminology, including evaluating agreement between 2 data sources for a dog and cat insurance database (Egenvall et al, 1998), describing completeness and correctness for the Swedish and Finnish cattle databases (Mörk et al, 2010;Rintakoski et al, 2012), and calculating sensitivity and positive predictive value (comparable to completeness and correctness, respectively) for an equine insurance database (Penell et al, 2007). Furthermore, in Sweden, the investigation of the spatial relationship between recorded mastitis incidence and SCC (Wolff et al, 2011), and investigation of risk factors for data loss in the Finnish system using logistic regression (Rintakoski et al, 2012) have been done. Specific guidelines do not exist for such work, but certain frameworks have been suggested within the context of human databases, where more validation work has been carried out (Sørensen et al, 1996;Hogan and Wagner, 1997;Arts et al, 2002).…”