The prevalence and control of bovine mastitis in Leptospira outbreak

Abstract

Leptospirosis is considered as one of the most widespread zoonotic disease among many species of wild and domesticated animals, including dairy cows worldwide. Due to its presence and proliferation capacity in the lactating mammary gland, leptospires-related mastitis and milk drop syndrome occur in lactating dairy cows. The aims of this study were to evaluate 1) the occurrence of mastitis due to leptospirosis and 2) the differences of Leptospira mastitis occurrence between primiparous and multiparous cows. Leptospirosis occurred in a large industrial dairy cattle herd complex in the northwest of Iran for 2 years including 760 Holstein dairy cows. The microscopic agglutination test (MAT) was used for diagnosis. Sera were screened against 22 life antigens. A MAT titer of ≥1:100 were considered positive. MAT titer was among 1:100 to 1:3200. The MAT showed that cows were infected by Leptospira interrogans (L. I.) hardjo, pomona, grippotyphosa, icterohaemorrhagiae, and canicola serovars. All of the tested cows had reaction against L. I. hardjo. In total, 406 (53%) out of 760 cows showed clinical mastitis. It was also observed that 255 (63%) dairy cows with ≥3rd lactation number had the highest mastitis. In primiparous cows, the prevalence of leptospiral clinical mastitis was significantly lower than multiparous dairy cows (P < 0.05) (19 vs 63%). During this 2 years leptospirosis outbreak, the control and treatment strategies limited the occurrence. They included the following: antibiotic therapy as treatment and prophylaxis, vaccination, control rodents population, and implementation of tight hygiene management.