Histopathological and molecular aspects of Sarcocystis sp. in cervids bred in captivity at Bioparque do Rio de Janeiro
Rusa timorensis, Sarcocystidae, diagnosis
Sarcocystis are intracellular protozoan parasites with an intermediate-definitive host life cycle based on a predator-prey relationship. Most Sarcocystis species infect specific hosts or closely related host species, causing various clinical signs to the hosts and in some cases rendering the meat unusable for consumption. A total of 27 cervids were submitted for post-mortem examination from 2017 to 2023 at the Pathological Anatomy Sector of the Universidade Federal do Rio de Janeiro. Four cervids in total were diagnosed with meningoencephalitis, representing 14.8% of the causes of death in the Cervidae family. Three Rusa timorensis from that group were diagnosed with meningoencephalitis caused by Sarcocystis sp. infection and presented compatible histological characteristics, according to the established criteria. Brain tissue samples from three deer with neurological signs were analyzed and encephalitis was observed on macroscopy with the presence of structures compatible with merozoites of Sarcoscystis sp. In addition, protozoan research was carried out in deer blood from the BioParque blood sample bank through molecular analysis. This study involves recording the appearance of Sarcocystis sp. in histopathological lesions associated with neurological signs in captive cervids from the city of Rio de Janeiro, in addition to their diagnosis, their macro and microscopic aspects and their clinical presentation and epidemiology.