Prevalence of intestinal pathogens in Danish finishing pig herds

Our aim was to determine the prevalence of the intestinal bacteria: Lawsoni a intracellularis, Brachyspira hyodysenteriae, Serpulina intermedia, Brachy spira innocens, Brachyspira pilosicoli, pathogenic Escherichia coli (serogr oups 0138, 0139, 0141 and 0149) and Salmonella enterica in Danish finishing pig herds. A total of 79 herds was randomly selected and visited during 19 98. From each herd, 20 faecal samples were collected from individual pigs w eighing 30-50kg. Furthermore, 10 pooled pen samples were collected and exam ined for S. enterica. In total, 1580 faecal samples and 790 pen samples wer e collected and examined by polymerase chain reaction (PCR) or culture. L. intracellularis was found in 74 herds (93.7%), B. hyodysenteriae in two her ds (2.5%), S. intermedia in 10 herds (12.7%), B. innocens in 27 herds (34.2 %), B. pilosicoli in 15 herds (19.0%), pathogenic E. call in 19 herds (24.1 %) and S. enterica in eight herds (10.1%). The within-herd prevalences of L . intracellularis and B. hyodysenteriae were 25-30%; the within-herd preval ences of the other agents were 5-10%. Three herds (4%) were not infected wi th any of the bacteria and 25 herds (32%) were only infected with L. intrac ellularis. (C) 2000 Elsevier Science B.V. All rights reserved.