Salmonella dublin infection in self contained dairy herds in East Anglia: excretion at calving.

Salmonella dublin was isolated from 14 (0.4 per cent) of 3656 rectal swabs taken from adult cattle in 20 self-contained East Anglian dairy herds with a history of the infection in calves. When 1486 calvings in these herds were monitored, the organism was isolated from 10 (0.7 per cent). Seven cows that had given negative rectal swabs at previous herd tests yielded the organism. These results indicate that latent carriers of S dublin may produce congenitally infected calves or excrete the organism at or soon after parturition and that this may provide the origin of many outbreaks of S dublin infection in self-contained herds.