Pasture area increases livestock rabies risk in Rio de Janeiro, Brazil: a geospatial analysis of neurological syndrome cases (2020-2024).

Animal rabies poses a risk to livestock in Brazil due to transmission by hematophagous bats. The Brazilian sanitary surveillance system mandates rabies testing for any livestock exhibiting signs of neurological syndrome. This geospatial, retrospective, longitudinal, observational study analyzed rabies test results for 204 cattle and 56 horses presenting with neurological syndrome in Rio de Janeiro State, Brazil, from 2020 to 2024. We calculated correlations and linear models between rabies results and municipal land-use types, as well the population of herbivores. Most neurological syndrome cases and positive rabies results occurred in cattle. The final linear model for the number of neurological syndrome cases and positive rabies results incorporated pasture area, shrub area and cattle population. Pasture area was positively correlated with higher numbers (p = 0.011 and p = 0.005, respectively). Larger shrub area was associated with fewer neurological syndrome reports and fewer positive results (p = 0.009 and p = 0.010, respectively). Greater cattle population showed a negative association with neurological syndrome notifications and positive detections (p = 0.085 and p = 0.046, respectively).A higher proportion of positive rabies tests was associated with larger pasture areas (p = 0.019) and with lower equine populations (p = 0.115). These findings indicate that the lower animal diversity in pasture areas provides few alternative feeding options for Desmodus rotundus besides livestock, leading to more neurological syndrome cases and animal rabies infections. A larger shrub area offer feed alternatives other than cattle to the bats and a larger cattle population dilutes the frequency of bat meals across individuals, reducing both neurological syndrome notifications and positive rabies detections.