Case-control study of an outbreak of clinical disease attributable to Salmonella menhaden infection in eight dairy herds.

OBJECTIVE

To identify risk factors associated with Salmonella menhaden associated disease in adult dairy cows during an outbreak in California.

DESIGN

Case-control study.

SAMPLE POPULATION

8 case dairies that had > or = 1 adult animal that had clinical signs of 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 breed (Jersey).

PROCEDURE

A questionnaire was developed and reviewed with 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 significant risk factors for clinical disease attributable to S menhaden infection.

CLINICAL IMPLICATIONS

Feed should not be overlooked as a potential source of Salmonella organisms in dairy herds.