Control of Salmonella Dublin in dairy herds

Salmonella enterica subspecies enterica serovar Dublin continues to be a common isolate from bovine diagnostic samples. Veterinary Investigation Diagnosis Analysis (VIDA) data showed 370 diagnoses of abortion due to Salmonella Dublin in the last five years, and 1,506 diagnoses for presentations other than abortions. The VIDA data includes diagnoses from beef herds, although the majority were from dairy cattle. The bacterium can cause a variety of clinical presentations, in both calves and adult cattle. This paper will focus on the impact of Salmonella Dublin on the health and welfare of dairy cattle, with a particular focus on calf health. Important aspects of the pathogenesis, clinical presentation and diagnosis of Salmonella Dublin will be reviewed. A small-scale pilot study was carried out with the objective of assessing the effectiveness of a control plan on calf health and welfare. Farms with a confirmed Salmonella Dublin outbreak within the last three months were enrolled on the study. A risk assessment was carried out, using a tool adapted from the Danish eradication programme. Areas of weakness in Salmonella Dublin control were identified, and suggestions for improvements made. The results of the study will be presented, and lessons learned about diagnosis and control discussed. While some parallels can be drawn with similar Danish work, differences exist in the manifestation of the disease in the sampled herds.