Anti-Toxoplasma gondii and anti-Neospora caninum antibodies in dogs with and without neurological signs

This study investigated the association between neurological signs as well as plausible risk factors and the seroprevalence of Toxoplasma gondii and Neospora caninum infection in dogs of the Campo Grande region of Mato Grosso do Sul, Brazil. In this study, the dogs were divided into two groups based on the presence and the absence of neurological signs (n=30 in each group). Serological diagnosis was performed using the indirect fluorescent antibody test. In the group with neurological disorders, 23.3% and 30% of the dogs had anti-T. gondii and anti-N. caninum antibodies, respectively. Moreover, three dogs from this group showed co-infection with both protozoa. In the group without neurological signs, 16.7% and 13.3% of the dogs were seropositive for T. gondii and N. caninum, respectively. Although presence of neurological signs was not associated with T. gondii and N. caninum infections (P = 0.747 and P = 0.21, respectively), there was a statistical association between T. gondii seropositivity and peripheral neurological alteration (P = 0.016) among dogs with neurological signs. Raw meat ingestion was the only risk factor associated with the presence of anti-N. caninum antibodies (P = 0.041). Results revealed evidence of exposure to N. caninum and T. gondii in dogs irrespective of the presence of neurological signs. Moreover, this study highlighted the need for serological investigation of T. gondii in dogs with disturbances in peripheral nervous systems and not offering raw meat to animals to avoid the risk of N. caninum infection.