Prevalence and Etiology of Subclinical Mastitis in Ewes of the Tabriz Region, Iran

To investigate the periodic prevalence, etiology and some epidemiological features of subclinical mastitis in ewes from the Tabriz region, milk samples from 260 lactating ewes were aseptically collected for bacterial and California mastitis test (CMT). An association was observed between the occurrence of subclinical mastitis and the age of ewe. The periodic prevalence rate of SCM was 9.23%. Staphylococci were the most prevalent bacteria, representing 88.4% of the isolates. Coagulase-negative staphylococci (CNS) (69.2%), was the most prevalent species followed by staphylococcus aureus (19.2%). Escherichia coli and Corynebacterium bovis was the second bacterial group in importance according with the distribution among flocks representing 8% and 8% of the isolates. In conclusion, subclinical mastitis seems to be, as deduced from the high prevalence observed in this study, an important health problem for milking sheeps in the Tabriz region.