Study on frequency, etiology and some enzymatic activities of subclinical ovine mastitis in Urmia, Iran

A total of 209 milk samples were collected from the udder halves of 178 native dairy ewes at 2 weeks after lambing until the 10th week postpartum. Those which were classified by bacterial culture and California Mastitis Test (CMT) as positive, were deemed to have glands with subclinical mastitis (SCM). The periodic prevalence rate of SCM was 39%. The most common bacterial isolates from SCM cases were coagulase negative staphylococci (41%), Bacillus cereus (33%), Staphylococcus aureus (22%) and Streptococcus spp. (4%). The mean activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were higher in milk from SCM udders than in milk from healthy udders (P < 0.01). There were no significant differences in blood serum LDH, ALP and aspartate aminotransferase (AST) of healthy and subclinical mastitic ewes. The increment in LDH and ALP in milk of udders shows the presence of tissue damage provoked by SCM. Thus, these parameters might be suitable for use in the early diagnosis of subclinical mastitis in ewes. © 2003 Elsevier Science B.V. All rights reserved