Efficacy Investigation of a chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio®) in the treatment of Otodectes cynotis in dogs

Abstract Background: Otoacariasis is a highly contagious, pruritic infestation of dogs caused by the ear mite Otodectes cynotis . Treatment with either moxidectin or sarolaner has been successful in dogs. Methods: In a dose confirmation study and a clinical field study, the efficacy of a chewable tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio ® ; Zoetis) against natural ear mite infestation was evaluated. In the dose confirmation study, efficacy was evaluated on Day 14 and 30 after a single treatment at a dose of 1.2 mg/kg sarolaner, 0.024 mg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt). In the field study, efficacy of the commercial dose of Simparica Trio was evaluated as parasitological cure rate after a single treatment and its non-inferiority to the control product (Advocate ® spot-on, 100 mg/mL (minimum 10mg/kg) imidacloprid + 25 mg/mL (minimum 2.5 mg/kg) moxidectin; Elanco Animal Health) was evaluated. If mites were still present on Day 30, a second treatment was provided, and efficacy was evaluated on Day 60. Results: In the dose confirmation study, otoscopy showed no mites in any of the Simparica Trio-treated dogs on Day 14 or Day 30, and a 100% efficacy ( P < 0.0001) was achieved against O. cynotis . In the field study, the parasitological cure rate in the Simparica Trio-treated dogs was 87.1% on Day 14 and 96.8% on Day 30 compared to 75.0% on Day 14 and 83.3% on Day 30 in Advocate spot-on-treated dogs. Three Simparica Trio-treated dogs were treated again on Day 30, resulting in a 100% efficacy on Day 60. The efficacy for Simparica Trio, as determined by parasitological cure rate, was non-inferior to Advocate spot-on solution on both Days 14 and 30. Conclusions: The results of the dose confirmation and clinical field study demonstrate the safety and high efficacy of Simparica Trio against natural infestations with O. cynotis in dogs.