Clinico-therapeutic studies on bacterial mastitis in bovines

Abstract

A study was carried out to detect subclinical mastitis by California mastitis test, to compare the different mastitis indicators, to identify the bacterial agents responsible and their antibiogram and to assess the efficacy of different treatments adopted. The occurrence of subclinical mastitis in organized farms and in and around Thrissur was found to be 25.17 per cent, after examining 1053 quarter milk samples by California mastitis test. A total of 265 milk samples were subjected to somatic cell count, modified Whiteside test and modified Aulendorfer mastitis probe test. These tests showed a positive correlation with somatic cell count. Staphylococcus aureus was found to be the chief etiological agent followed by coagulase negative staphylococci, coliforms and Streptococcus agalactiae. Chloramphenicol and enrofloxacin were found to be the most effective antibiotics against bacterial isolates from mastitis cases and sulphadiazine and trimethoprim the least effective. In vivo studies revealed that oxytetracycine is more effective followed by enrofloxacin and amoxycillin-cloxacillin combination. But the bacteriological cure was same for all the treatments. The twenty four Staphylococcus aureus isolated from clinical mastitis were grouped into seven different genotypes using RAPD analysis. The four Escherichia coli isolates gave single RAPD pattern. S. aureus genotype a was found to be more prevalent.