An abortion storm in dairy cattle associated with neosporosis in southern Brazil

Abstract

Between December 2016 and April 2017, a spate of abortions occurred in a closed dairy herd from the central eastern region of Paraná, Brazil, in which 75 cows aborted. To identify its cause, organ fragments were collected from an aborted fetus for histopathology, and the blood samples from a stillborn, 4 aborted fetuses, and 9 farm dogs for indirect fluorescent antibody technique (IFAT). These tests found multifocal non-suppurative encephalitis, periportal hepatitis, and multifocal lymphoplasmacytic myocarditis, and detected anti-Neospora antibodies in all aborted fetuses, and in 5 of the 9 dogs. DNA of Neospora caninum was detected in the brain tissue of an aborted fetus. Blood samples of 340 cows and 146 heifers showed 33.5% and 30.8% seropositivity, respectively. In this closed herd, the parasite was probably introduced by infected domesticated or wild carnivores inhabiting the farm, through the infective oocysts present in their stool.

Neospora caninum infection in aborting bovines and lost fetuses: A systematic review and meta-analysis

“…caninum infection in bovines that had an abortion according to the diagnostic methods of ELISA and IFA were determined to be 47% (95% CI: 35%–58%) and 45% (95% CI: 30%–60%), respectively. One study did not mention the type of serology test and the prevalence was 60% (95% CI: 49%–71%) [ 47 ]. The results of the subgroup analysis revealed that the effect of assessment of the detection methods on the heterogeneity of studies was not statistically significant ( p = 0.533).…”

Experimental Neospora caninum Infection in Pregnant Cattle: Different Outcomes Between Inoculation With Tachyzoites and Oocysts

“…Bovine abortion outbreaks due to neosporosis continue to be a serious economic problem. Exposure of cattle to oocysts shed by dogs or wild definitive hosts may cause point source exposure of pregnant cows and the occurrence of abortion storms ( 37 – 40 ).…”