A case-control study of Nocardia mastitis in Nova Scotia dairy herds

A case-control study was conducted to identify herd production, housing, and hygienic and therapeutic factors associated with Nocardia mastitis in dairy herds in Nova Scotia. The data were collected by on-farm interview with owners of 54 case and 54 control herds. Logistic regression was used to study risk factors. The use of dry cow products containing neomycin, including 2 specific dry cow products, was strongly associated with Nocardia mastitis in a herd. Other factors which increased the risk were higher levels of production, larger herd size, and a large percentage of cows treated with dry cow products. These results are compared to results from a similar study in Ontario..