Increase in the diagnosis of equine infectious anemia over an 11-year period in the western region of Rio Grande do Sul, Brazil

Abstract

ABSTRACT Equine infectious anemia (EIA) is a disease that affects members of the Equidae family. In Brazil, it is detected in all regions, and distribution is associated with environmental factors and socio-cultural aspects. The study aimed to describe and analyze the occurrence of EIA outbreaks between 2009 and 2019 in the western region of Rio Grande do Sul. Data from 125 official reports of focus (113) and suspected (12) cases were analyzed. The majority of cases (102) occurred between 2015 and 2019. July, August, and September accounted for 65% of the records, and the diagnosis was made as a requirement for transporting the animals. In all, 2071 animals were on the focus properties, and 242 horses were identified as positive. Of these, 237 were euthanized, and five vanished from the properties. Properties with up to 10 horses were the most affected (71.7%, 81/113), and these herds contained 41.1% of the positive animals (104/242). Properties located in the peri-urban region of the cities accounted for more than 60% of the cases. One outbreak was diagnosed in horses smuggled from Argentina. The results characterize the occurrence of EIA in the region and demonstrate the maintenance and spread of the virus's circulation among herds.