Evaluation of the efficacy of Simparica Trio® in the prevention of the transmission of Babesia canis by infected Dermacentor reticulatus to dogs

Background Babesia canis is a clinically relevant vector-borne pathogen in dogs, and its presence is expanding. The efficacy of Simparica Trio (R) (Zoetis) in the prevention of B. canis transmission was evaluated at the minimum recommended label dose of 1.2 mg/kg sarolaner, 24 mu g/kg moxidectin and 5 mg/kg pyrantel per kg bodyweight. Methods Twenty-four (24) dogs were randomly allocated to either a placebo-treated group or one of two treatment groups with Simparica Trio. Dogs were infested with B. canis-infected Dermacentor reticulatus ticks 21 or 28 days after treatment administration. Blood samples for antibody and DNA detection were collected from each dog prior to tick infestation until 28 days after infestation. A dog was defined as being B. canis positive if it tested positive by both an indirect immunofluorescence assay (IFA) and PCR at any time during the study. Results No treatment-related adverse reactions were recorded during the study. All placebo-treated animals displayed clinical signs due to babesiosis and tested positive on both IFA and PCR. None of the Simparica Trio-treated animals displayed any clinical symptoms or tested positive, resulting in a 100% efficacy in the prevention of canine babesiosis (P < 0.0001). Conclusions A single treatment with Simparica Trio at the minimum recommended label dose of 1.2 mg/kg sarolaner, 24 mu g/kg moxidectin and 5 mg/kg pyrantel per kg bodyweight prevents the transmission of B. canis by infected D. reticulatus to dogs for at least 28 days.