Seroprevalence and intercurrence of reproductive pathogens in cattle from family farms in North of Minas Gerais, Brazil

The aims of the present study were: to estimate the seroprevalence of Bluetongue virus (BTV), bovine alphaherpesvirus 1 (BoHV-1), bovine viral diarrhea virus (BVDV), Brucella abortus and Leptospira spp. in cattle from family farms in North of Minas Gerais; to determine the intercurrence and association among these pathogens; and to assess the possible associated factors to seropositive herds and animals. For this, 476 cows from 46 farms were sampled and evaluated serologically. The seroprevalence in herds and cattle was, respectively, for BTV 100% and 52.0%, for BoHV-1 95.7% and 48.6%, for BVDV 78.3% and 46.1%, for Leptospira spp. 76.1% and 29.1%, and for B. abortus was 0% in herd and cattle. More than 65% of the herds was simultaneously seropositive for BTV, BoHV-1, BVDV and Leptospira spp. Seropositivity for BoHV-1, Leptospira spp. serovar Autumnalis and serovar Hardjoprajitno were associated with abortion, whereas seropositivity for BVDV was associated with BoHV-1. Moreover, association among seropositivity for BVDV, BoHV-1 and Leptospira spp. was also observed. In conclusion, BTV, BoHV-1, BVDV and Leptospira spp. are highly seroprevalent and occurred simultaneously in cattle from family farms in Minas Gerais, indicating the need for the implementation of control measures to avoid economic losses related to these diseases.