Distribution, transmission, and risk factors of infection with canine vector-borne pathogens in wild foxes and free-ranging dogs in Chile

DI CATALDO, SOPHIA; AITOR CEVIDANES; CLAUDIA ULLOA-CONTRERAS; JAVIER MILLÁN

Buenos Aires

Simposio; Frontiers in Bioscience 4; 2023

Max Plank Institute

Canine vector-borne pathogens (CVBP) comprise a major group of worldwide-distributed pathogens that are transmitted by arthropods and affect wild and domestic canids. Despite this, information about the presence, distribution, and impact of CVBP in dogs and foxes in the Chile is very scarce and has probably been underestimated. Here we sampled 981 dogs, 155 Andean foxes (Lycalopex culpaeus), 90 grey foxes (L. griseus), and 82 Darwin’s foxes (L. fulvipes) from six different bioclimatic regions of Chile. Molecular tools and immunofluorescence antibody tests were used to detect the CVBPs. The presence/exposure of Anaplasma platys in all six bioclimatic regions was confirmed. Ehrlichia canis was not molecularly detected in any sample. Data suggest that free-ranging dogs in Chile could be favoring the maintenance of A. platys in all areas suitable for its tick vector. Although apparently infrequent, spillovers from dogs to foxes may be taking place and should be considered in management plans in Chile. The widespread canine hemoplasmas in Chile were demonstrated. A higher prevalence was detected in regions where ticks were absent and in male dogs, suggesting that blood ingestion from aggressive interactions may be an alternative route of transmission. The presence of shared hemoplasma haplotypes between dogs and foxes showed that interspecific transmission is occurring. Likewise, hemoplasmal DNA was screened and characterized in Darwin’s foxes, an endemic and extremely endangered canid of Chile. In this species, hemoplasmas resulted endemic, showing a predominant intraspecific transmission, and an apparent lack of associated pathology. Finally, the presence of Hepatozoon, piroplasmids, and filariids was analyzed, describing the first records for Chile of Babesia vogeli in dogs and of Hepatozoon in foxes. This project contributed to filling the knowledge gap in the epidemiology of vector-borne pathogens shared between domestic and wild animals in Chile, having implications for the transmission ways of the studied agents.