Scenario of viral and protozoa diseases in commercial dairy goats from Zona da Mata of Minas Gerais State, Brazil

Abstract

Caprine encephalitis-arthritis virus (CAEV), bluetongue virus (BTV), and the parasites Neospora caninum and Toxoplasma gondii can be considered important infectious agents for dairy goats, causing significant losses in production. Bovine herpesvirus 1 (BHV-1) and vesicular stomatitis virus (VSV) can occasionally infect goats. This study assessed the prevalence and determined the risk factors for viral (CAEV, BTV, BHV-1, and VSV) and protozoan (T. gondii and N. caninum) infection; it also verifies the natural disposition of seropositive groups regarding their multivariate similarity in commercial dairy goat farms in the Zona da Mata of Minas Gerais, Brazil. Blood serum samples from 413 dairy goats from nine farms were analyzed using the virus neutralization test, agar gel immunodiffusion, and indirect immunofluorescence methods. The average prevalences found were 65% (269/413) and 47.1% (195/413) for the parasites N. caninum and T. gondii and 35% (145/413) and 24% (99/413) for BTV and CAEV, respectively. All samples were seronegative for BHV-1 and VSV. Significant risk factors were found only in T. gondii and CAEV infection. For toxoplasmosis, contact of the herd with cats (OR = 28.6; [95% CI = 5.81–140.66]) or dogs and cats (OR = 21.12; [95% CI = 6.78–65.82]), the disposal of dead animals in landfill (OR = 0.03; [95% CI = 0.01–0,10), the lack of colostrum treatment (OR = 3.75 [95% CI = 1.53–9.20]), and natural reproduction (OR = 0.28; [95% CI = 0.13–0.62]) were risk factors. For CAEV, the risk factors were contact with dogs (OR = 0.66; [95% CI = 0.49–0.90]), the disposal of dead animals in landfill (OR = 4.12; [95% CI = 1.65–10.28]), and natural suckling (OR = 0.03; [95% CI = 0.004;0.261]). Based on the PCA results, farms with higher rates of positive cases in CAEV, N. caninum, and T. gondii infection bordered the mesoregion, demonstrating the possible special interaction with the seropositivity of dairy goat herds. There is a need to implement measures to control viral and protozoal infections in this important goat milk production region in Brazil.