Effective control of a gentamicin-resistant Salmonella arizonae infection in turkey poults

A gentamicin-resistant Salmonella arizonae isolate was identified as the cause of an unusually high early mortality rate in several flocks of poults produced by a primary turkey breeder. The company routinely dipped its hatching eggs in 500 ppm gentamicin before incubation and injected each poult at 1 day of age with 1 mg gentamicin. Mortality was reduced to normal, but S. arizonae was not eliminated by injecting the day-old poults with higher doses of gentamicin. S. arizonae was not isolated from sample normal-sized poults in treated groups when tetracyclines were used for antibiotic inoculation of day-old poults. Tetracyclines seemed to be completely effective only when a 5-mg subcutaneous injection per day-old poult was combined with an approximately equal dose in drinking water daily for 4 days, and therapy was accompanied by the culling of runts and other debilitated poults.