Frequency of jowl abscesses in feeder and market swine exposed to group E streptococci as nursing pigs.

Weaning and isolation were evaluated as management methods in controlling streptococcic lymphadenitis of swine. Nursing pigs in 3 experiments were exposed to group E streptococcus (GES) by contact with their GES-inoculated dams or other GES-inoculated pen mates. The exposed pigs were either weaned and isolated when 5, 6, or 8 weeks old or left in contact with the inoculated swine until 14 to 32 weeks old when all were necropsied. Abscesses were not recognized in 13 weaned or 7 unweaned pigs necropsied at 14 to 15 weeks of age, but GES was isolated from mandibular lymph nodes of 4 of the 7 unweaned pigs. Abscesses were recognized in 1 of 49 unweaned and 4 of 53 weaned swine when examined at market weight (24 or 32 weeks of age). In the 3rd experiment, 10 of 11 inoculated sows, one of 33 unweaned, and 11 of 25 weaned swine had serum titers greater than 4 to GES in a microtitration agglutination test.