Seroprevalence and incidence of Toxoplasma gondii and Neospora caninum infection in naturally exposed domestic dogs from a rural area of São Paulo state, Brazil

Abstract

Dogs are hosts of the protozoans Toxoplasma gondii, which causes an important public health disease, and Neospora caninum. Studies that have evaluated toxoplasmosis and neosporosis for prolonged periods in dog populations are rare. We analyzed infection by both parasites in a domestic dog population over three consecutive years in São Paulo state, Brazil. In the 1st, 2nd and 3rd years of collection, 181, 193 and 172 domiciles were visited, and blood samples of 331, 371 and 348 dogs were collected for antibody serology, respectively. The seroprevalence of T. gondii in each year was 27.2%, 22.5% and 43.9%, respectively, and that of N. caninum was 7.8%, 4.8% and 6.8%, respectively. The incidence rates for T. gondii in the 2nd and 3rd collections were 13.2% and 30.0%, and those for N. caninum were 3.3% and 4.4%, respectively. Positive and negative serological conversions for both agents occurred at high frequencies during the study period. This study reveals the canine population’s serological profile and demonstrates the constant exposure of dogs to the investigated pathogens, indicating the need for prevention and control measures in the region.

Toxoplasma gondii and Neospora caninum antibody seroprevalence and risk factors among dogs treated at Public Veterinary Hospitals in São Paulo, Brazil

“…In the state of São Paulo, seroepidemiological surveys carried out among dogs over the last 20 years have used very different samples, regarding the number of dogs, whether neurological problems were presented or not, where the dogs were living (rural or urban environment) and whether data collection was in connection with a vaccination campaign, among other different characteristics. In these studies, the occurrence rates for anti-T. gondii antibodies ranged from 5.1% to 50% (Silva et al, 2010;Aguiar et al, 2012;Langoni et al, 2012Langoni et al, , 2013Paulan et al, 2013;Zanette et al, 2014;Seabra et al, 2015;Olbera et al, 2020;Sevá et al, 2020). The low prevalence found among domiciled dogs in the present study, even among those that were allowed out into the streets, is an interesting result because it indicates that few dogs have contact with T. gondii oocysts in the environment or with cysts in infected meat.…”