Experimental inoculation of Neospora caninum tachyzoites in eared doves (Zenaida auriculata).

Neospora caninum is an apicomplexan parasite distributed worldwide. Although a positive association between the presence of birds and abortions in cattle associated to N. caninum has been reported, the role of the birds in the epidemiologic cycle of the parasite is unknown. To the best knowledge, no experimental studies have evaluated N. caninum in the eared dove, Zenaida auriculata. Therefore, we aimed to determine whether Z. auriculat can act as intermediate host for N. caninum. Eighteen birds were divided into four groups, G1, G2, G3, and G4 (control); G1, G2 and G3 received 2 × 10 ⁶ tachyzoites of NC-1 strain via different routes: subcutaneous, intramuscular, and intraperitoneal, respectively. G4 composed of three birds. Serum samples were collected weekly, and one bird each from G1, G2 and G3 was euthanized on the 7th and 14th day post-inoculation (dpi). The remaining birds were euthanized after the 28th dpi. Tissues from the doves were evaluated using histopathological analysis, PCR and dog bioassay to detect the parasite. Dogs were fed with tissues from the birds and monitored for 30 days. Serum samples were collected weekly from the dogs for serological analysis, and feces samples were collected daily until the end of the experiment for coproparasitological examinations. No dove showed clinical signs of the infection; however, all of them seroconverted after the inoculation, with stronger immunological response in the G3 birds. The lung tissue of one G3 bird showed positive PCR results; it was euthanized on the 7th dpi, and an inflammatory infiltrate was observed in the lung and kidney from this dove. The dogs did not shed oocysts or seroconverted. Our results indicate that the intraperitoneal route induced infection in the doves; however, the parasite may have been eliminated by the host, and the doves may be resistant to chronic infection.
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