PUBLIC VETERINARY-MEDICINE - FOOD SAFETY AND HANDLING - BACTERIOLOGICAL CULTURE AND HISTOLOGIC EXAMINATION OF SAMPLES COLLECTED FROM RECUMBENT CATTLE AT SLAUGHTER

Objective - To evaluate the potential food safety risks constituted by recumbent cattle that are slaughtered for edible beef. Design - Prosp ective case series. Animals - Thirty cattle in recumbency that passed a routine antemortem inspection at a US federally inspected abbatoir. Procedure - Aerobic, bacteriologic culture of blood samples taken imme diately prior to slaughter and of spleens taken during viscera inspect ion. Gross lesions were recorded, and samples of liver, lung, kidney, and heart were collected from each animal for routine light microscopi c examination. Results - Bacteremia caused by Salmonella dublin was do cumented in 1 cow that had arthritis. Two other cows were condemned af ter postmortem inspection: 1 because of pneumonia and pleuritis and th e other because of vegetative endocarditis. Three carcasses were retai ned and later condemned because of antibiotic residues in tissues: 1 o f these cows had mastitis, 1 had liver abscesses, and 1 was the cow wi th vegetative endocarditis. Sarcocystosis was found in 27 of 30 hearts , but other clinically important histologic lesions were observed only in liver samples. In 11 of the 30 cows, multifocal, microscopic foci of hepatitis were observed, suggesting that terminal embolic bacterial showering of the liver had occurred in these animals. Liver samples w ere not submitted for bacteriologic culture. Clinical Implications - M ost recumbent cows slaughtered for edible beef are not contaminated by bacteria; however, the viscera from these animals may present a food safety danger. Efforts should be made to develop rapid tests to identi fy bacteremic animals at slaughter and to more fully evaluate terminal showering of viscera by bacteria in cattle at slaughter.