Tick-borne pathogens in dogs and their ticks in France: Molecular and serological evidence from a multicenter participatory study: A Quick Guide

A year-long study in France offers a closer look at the ticks found on dogs—and the tick-borne organisms detected in both dogs and their ticks.

From December 2022 to December 2023, researchers worked with 41 veterinary practices across 34 French departments. The pilot project included 82 dogs and collected 165 ticks. It brought together veterinary clinics, dog owners, and research laboratories in a participatory surveillance effort.

Dogs may be useful for monitoring tick activity because they frequently spend time outdoors, are exposed to ticks, and live closely with people. Researchers noted that canine tick-borne diseases are expanding globally and are a growing concern for veterinary and public health.

The most commonly identified tick was *Dermacentor reticulatus*, accounting for 29.7% of collected ticks. Other species included *Ixodes ricinus*, *Rhipicephalus sanguineus* sensu lato, *Ixodes hexagonus*, and *Dermacentor marginatus*.

Ticks were submitted throughout the year, with different tick genera showing different patterns over time. This finding supports the value of monitoring tick activity across seasons, rather than only during a single period of the year.

Researchers tested tick samples and canine blood and/or serum samples using molecular and serological methods. In dogs, molecular testing identified *Borrelia garinii* in five dogs and *Babesia canis canis* in five dogs. Antibodies against *Ehrlichia* species were detected in one dog, while antibodies against *Anaplasma* species were found in three dogs.

Notably, several dogs with detected pathogens or antibodies did not have symptoms. This suggests that looking only for visibly ill animals may miss some pathogen circulation among dogs and ticks.

The ticks also carried several pathogens, including *Borrelia garinii*, *Babesia canis canis*, *Rickettsia massiliae*, and *Rickettsia raoultii*. Researchers also detected several tick endosymbionts.

This was not a national prevalence study, so it cannot show how common these pathogens are across France. It also did not compare canine findings with human surveillance data, meaning it cannot determine whether a dog’s results predict a person’s health status.

Still, the study provides proof of concept for a One Health approach that connects veterinary and public-health surveillance. Monitoring dogs, ticks, and pathogens over time may help improve understanding of tick exposure and pathogen circulation.

This information is for educational purposes only and is not medical or veterinary advice. Speak with a physician or veterinarian about concerns involving tick exposure, symptoms, testing, or treatment.