Comparative Evaluation of Antibiotic Therapies for Subclinical Staphylococcal Mastitis in Goats

Subclinical mastitis (SCM) is characterized by inflammation of the udder without visible signs of inflammation in the animal, udder and milk and hence could be diagnosed by laboratory examination only. Effective treatment of SCM in goats is crucial for maintaining quality milk production. This study was conducted at the Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur (M.P.), India. A total of 236 lactating goats irrespective of age, breed, parity and stage of lactation, from both organized and unorganized sectors in and around Jabalpur, were screened over a period of six month. Based on modified California mastitis test scores, 83 goats tested positive for subclinical mastitis resulting in an overall occurrence of 35.17% (83/236). A total of 48 milk samples that tested positive for modified California mastitis test were further analyzed for bacterial isolation and identification. Among them, 34 (70.83%) samples were positive for only Staphylococcus spp., while 12 (25%) samples exhibited mixed infection with Staphylococcus spp. and Gram-positive bacilli. Then, 18 goats, positive for subclinical Staphylococcal mastitis were divided into three groups i.e. G1, G2 and G3 with six goats in each group for therapeutic study and six apparently healthy goats were taken as healthy control group (G4). G1 Goats were treated with Inj. Enrofloxacin LA @ 7.5 mg/kg b. wt. I/M single dose; G2 with Inj. Ceftizoxime @ 10 mg/kg b. wt. I/V single dose and G3 with Inj. Oxytetracycline LA @ 20 mg/kg b. wt. I/M single dose. The responses of therapeutic assessment were evaluated on the basis of somatic cell count and modified California mastitis test score. The most effective response for subclinical Staphylococcal mastitis in goats was observed with Ceftizoxime followed by Enrofloxacin LA and the least with Oxytetracycline LA.