Evaluation of the dry-off intramammary antibiotic therapy for controlling of ovine mastitis

The study was conducted on 011 pregnant Awassi ewes, aged 2-5 years to evaluate a prepartum intramammery treatment for controlling postpartum mastitis. Four hundred mammary secretions or milk samples were collected aseptically (200 samples, 2-3 weeks prepartum and 200 samples, one week postpartum). These were subjected to bacteriological culturing and identification. California mastitis test and white side test were used for diagnosis of subclinical mastitis. Immediately after the prepartum sampling, dry-off intramammary antibiotic was administered to 87 randomly selected udder halves (42/92 infected halves and 45/108 non-infected halves), the remainder 50 and 63 halves were allowed without treatment as infected and non-infected control respectively. Results of culturing revealed 148 and isolates of 20 different bacterial species. Eighty-nine were gram positive and 59 were gram negative. Coagulase negative staphylococci were the most frequent gram positive bacterial isolate 40 (27%), while the predominant gram negative bacteria were Mannheimia haemolytica 16 (10.81%). The Prepartum clinical and subclinical mastitis were 13% and 33% respectively, compared with 5.5% and 22.5% in post partum period. Results of the prepatum treatment of infected udder halves revealed that, out of 42 treated halves, 38 (90.5%) halves were recovered of infection and only 4 treated halves experienced infection during the postpartum period, of these 2 (4.8%) halves retained the same pathogen and the other 2 (4.8%) developed new infection with diverse bacteria. While 42 (93.33%) of 45 prophylactically treated healthy haves were protected from developing postpartum infection and only 3(6.66%) haves contracted infection through the post partum period. In conclusion, Dry-off prophylactic treatment could reduce the incidence of postpartum ovine mastitis. The self-cure phenomenon has an important role in resolving mastitis in ewes.