Do dogs and foxes share pathogens through fleas and ticks?

Methods

Summary

The study will be carried out in rural and peri-urban areas of Argentina. Three species of canids will be included: free-ranging dogs, Andean foxes (Lycalopex culpaeus), and gray foxes (L. griseus).

Foxes will be captured using Victor Oneida spring traps and rural/peri-urban free-ranging owned dogs will be sampled. In all these canids species, blood samples and ectoparasites will be collected.

All obtained samples will be analyzed through molecular means (PCR) to detect canine vector-borne agents (CVBP) such as Ehrlichia, Anaplasma, Babesia, Hepatozoon, and hemoplasmas. 

Scientific lectures will be given to the rural and peri-urban communities where the canid samples were taken. The impact of their pets roaming freely in natural areas will be explained to people, providing them with the information obtained from this project. Finally, anti-parasite controls and vaccinations will be administered to reduce this negative impact. 

Challenges

Achieving the necessary sampling size to infer conclusions in a population can be difficult when working with wild canids. This is why, to ensure an adequate sampling number, samples of foxes will also be obtained through collaboration with rescue centers and the Natural Resources Department. In turn, necropsies will be performed on road-killed individuals, taking spleen and ectoparasite samples whenever possible.

Pre Analysis Plan

The prevalence of the CVBP studied between canid species and ectoparasites will be analyzed by Chi-square tests. Mean ectoparasite abundance and incidence data will also be calculated.

The evaluation of risk factors for infection (or ectoparasite infestation) will be carried out by means of generalized linear models using R software. The dependent variables will be binary (presence=positive/negative for each pathogen, and presence/absence for ectoparasites). The independent variables will include intrinsic factors (age, sex, and body condition) and extrinsic factors (sampling site, climatic and environmental factors).

Finally, the sequences of each CVBP obtained will be analyzed by means of phylogenetic trees in order to try to infer interspecific transmission.