CONICET | Buscador de Institutos y Recursos Humanos

The occurrence of combined infections by Toxoplasma gondii, Neospora caninum and Canine distemper virus(CDV) in domestic dogs and wildlife animals has not been frequently reported, and the histopathological findings were notexhaustively described. The objective of this study was to report a co-infection of CDV, T. gondii and N. caninum in a dogwith neurological signs, as well as the molecular characterization of the protozoa involved. A young street dog was rescuedwith neurological clinical signs and died spontaneously. A complete necropsy was performed. Tissues were collected andfixed for histopathological evaluation. Additionally, sections of the central nervous system (CNS) and heart were assayedby immunohistochemistry (IHQ) for T. gondii and N. caninum. Sample of brain tissue was analyzed by PCR and nPCRRFLP for T. gondii genotyping. Spleen was used for detection of CDV by RT-PCR. Gross lesions were not observed, withthe exception of the lung. Microscopically, a severe necrosuppurative meningoencephalitis with vasculitis, tachyzoites andbradyzoites of T. gondii and N. caninum were found. Demyelination was also evident, associated with eosinophilicintranuclear inclusion bodies within astrocytes. CDV was PCR positive while both parasites were presented PCR and IHQpositive results. Molecular characterization of T. gondii was reported as atypical #14 (likely). To our knowledge, this is thefirst report of genetical identification of T. gondii obtained from the brain of a naturally infected dog in Argentina. Theresults emphasize the importance of different techniques as diagnostic tools to enhance the detection of causative agents incases of fatal encephalitis.