Risk factors associated with prevalence and major bacterial causes of mastitis in dromedary camels (Camelus dromedarius) under different production systems

A cross-sectional study was conducted in desert environment of Jhang (Pakistan) from November 2008 to October 2009 on she-camels kept under pastoralist conditions to determine the prevalence of mastitis, impact of risk factors, and isolate the dominant mastitis-causing bacteria on total of 150 lactating she-camels by using clinical examination and surf field mastitis test. From the 150 she-camels examined, 69 (46%) were positive for mastitis at animal level, 12 (8%) clinical, and 57 (38%) subclinical. Age, parity number, stage of lactation, breed, production system, hygiene of milking process, and presence of lesion on udder/teat were found significantly associated (p < 0.05) with the prevalence of mastitis in she-camels. There was the lowest prevalence (33.33%; 15 of 45) of mastitis in she-camels of 5-7 years of age, while the highest (80%; 12 of 15) in the animals aged between 14 to 16 years. Stage of lactation significantly affected (p < 0.05) and was found to be associated with the prevalence of mastitis being the highest (54.55%; 18 of 33) during the initial stage of lactation (0 to 1 month) followed by last 2 months (10-12 months) as 54.17% and mid-stages (1-3 and 3-10 months) of lactation as 28.57% (6 of 21) and 37.50% (9 of 24), respectively. According to breed of camels, it was noted that the prevalence of mastitis affected significantly (p < 0.05) being the highest in crossbred (Desi x Mareecha) as 51.39% (37 of 72) followed in order by Mareecha and Desi as 43.14% and 37.04%, respectively. Staphylococcus (42.19%) and Streptococcus (15.63%) genera were the dominant isolates identified. Good hygiene in milking process, milking clinically infected she-camels at last, culling chronic mastitis carriers, treating clinically infected she-camels, and dry period therapy could reduce the prevalence of contagious mastitis in the study area.