CASE-CONTROL STUDY OF AN OUTBREAK OF CLINICAL-DISEASE ATTRIBUTABLE TOSALMONELLA MENHADEN INFECTION IN 8 DAIRY HERDS

Objective--To identify risk factors associated with Salmonella menhade n associated disease in adult dairy cows during an outbreak in Califor nia. Design-Case-control study. Sample Population--8 case dairies that had greater than or equal to 1 adult animal that had clinical signs o f salmonellosis and from which S menhaden was isolated and 22 control dairies, 16 of which were matched on the basis of herd size and county and 6 of which were matched on the basis of herd size, county, and br eed (Jersey). Procedure--A questionnaire was developed and reviewed wi th the herdsman or owner of each dairy. Primary areas of concern were herd management, disease characteristics, and feed-related information . Results--Use of 1 particular feed mill and feeding animal fat were s ignificant risk factors for clinical disease attributable to S menhade n infection. Clinical Implications--Feed should not be overlooked as a potential source of Salmonella organisms in dairy herds.