Clinico-therapeutic studies on bacterial mastitis in goats

Abstract

The lactating does in the University goat and sheep farm were screened for subclinical mastitis once in three months using the California mastitis test. The occurrence of subclinical mastitis was found to be 30.2 per cent. Statistical analysis showed no significant association between occurrence of subclinical mastitis and teat length whereas there was significant association between distance from teat tip to floor. Among 642 samples screened 194 samples were found to be positive by CMT. The arithmetic mean cell counts for each CMT score ranged between 0.736 ± 0.033 x106 and 20.417 ± 0.851 x106 cells/ml. Among CMT positive samples MWST and MAMP detected 62.89 per cent and 43.29 per cent as positive for subclinical mastitis. Comparison of screening tests revealed that significant positive correlation existed among the four tests namely CMT, MWST, MAMP and SCC. Comparison with culture results showed that score ‘3’ of CMT score ‘3+’ of MWST and grade 3 of MAMP reaction detected the maximum positive cases. CMT scores and SCC in bacteriologicaly positive samples showed significant association. Among the TIST positive milk samples 20 (44.44 per cent) were culture positive. Staphylococcus aureus was the most predominant isolate in both clinical and subclinical caprine mastitis. In vitro antibiotic sensitivity pattern revealed that chloramphenicol was the most sensitive antibiotic followed by ceftriaxone and ciprofloxacin. The isolated pathogens showed maximum resistance to sulpha. Comparison of treatment trials in 24 clinical goat mastitis cases using ceftriaxone and ciprofloxacin with 12 animals in each group revealed that clinical and bacteriological cure was better in the case of ciprofloxacin. Clinical and bacteriological cure was comparatively less in gangrenous mastitis cases. Eighteen Staphylococcus isolates from clinical mastitis cases and 23 Staphylococcus isolates from subclinical cases were typed by RAPD fingerprinting. Twelve different genotypes were obtained among which genotype c predominated in clinical mastitis whereas in subclinical cases b and i were the common Staphylococcal genotypes. Clinical and bacteriological cure rates were 100 per cent for RAPD type l in the ceftriaxone treated group and genotypes c and i in the ciprofloxacin treated group of animals. A possible relationship regarding the genetic make up of the different Staphylococcal isolates was elucidated from the phylogenetic tree generated from the RAPD fingerprints.