Efficacy of oxytetracycline and gentamicin against Brucella suis infection in pigs.

Eighteen aborted sows naturally infected with B. suis biovar. 2 were allotted in two groups each of 9 animals. All sows were treated with oxytetracycline given in feed (20 mg/Kg BW daily) during 45 days after abortion, and the half of animals received a combined intramuscular treatment with gentamicin (4 g/day) during the last 15 days of treatment. Ten days after treatment, sows were slaughtered and several lymph nodes, uterus and spleen submitted to bacteriological studies. All animals treated with oxytetracycline alone were found infected in one or more necropsy samples. By contrast, 100% of the animals receiving the combined treatment with gentamicin were fully cured from infection. In conclusion, monotherapy with oxytetracycline is not effective enough against B. suis biovar. 2 infection in sows, while combining this treatment regime with gentamicin during 15 days is fully effective against infection.