Prevalence survey of abortions caused by Leptospira, Brucella and Campylobacter spp. in the dairy cattle by molecular method

Abortions caused by Brucella spp.، Leptospira Interrogans serovars and Campylobacter fetus subspp. veneralis are the most important bacterial abortions in the cattle. For this reason from May 2008 through August 2010، 76 aborted fetuses randomly were collected. After necropsy، tissue samples were taken from the liver، stomach، lung، kidney، spleen، brain of the aborted fetuses and placenta (from the aborted dams). Tissue samples were kept at -20˚ C in the refrigerator until to performing the PCR test. Six (7. 8%)، sixteen (21%) and three (3. 9%) out of 76 aborted fetuses showed positive reaction by the PCR test to the Brucella spp.، Leptospira interrogans and Campylobacter fetus subspp. veneralis respectively. Prevalence of the Leptospira-induced abortions was high in the old cows and advanced pregnancies (7-9 months). However statistical difference was not observed among these groups or different periods of pregnancy (P>0. 05). In conclusion، our results indicated that the Leptospira interrogans group is the most prevalent abortive factor among the Tabriz dairy herds and sometimes the RB51 vaccine can be abortive in the pregnant cows.