Efficacy of fluralaner against natural infestations of Haemaphysalis longicornis and Rhipicephalus sanguineus in dogs under field conditions in China.

Tick infestations compromise canine health and facilitate zoonotic pathogen transmission. This randomized, investigator-blinded, multicenter field study evaluated the efficacy and safety of fluralaner chewable tablets against natural tick infestations in dogs in China. Dogs naturally infested with ≥ 5 ticks were enrolled and randomized 1:1 to receive either a laboratory-developed fluralaner chewable tablet (experimental) or the reference product BRAVECTO® (control), with dosing according to body-weight bands. At baseline (Day 0), whole-body tick counts (≥10 min), lesion-severity scoring, and microscopic identification of a tick subsample were performed; follow-up assessments occurred on Days 7, 14, 28, 56, and 84, with the final visit on Day 56 for dogs infested with Rhipicephalus sanguineus and on Day 84 for those with other species, notably Haemaphysalis longicornis. A total of 120 dogs were enrolled, and two tick species were identified: H. longicornis and R. sanguineus. Relative to baseline, mean tick counts were reduced by 99.95 % (experimental) and 99.83 % (control); 98.33 % of dogs were tick-free on Day 7, and 100 % were tick-free from Day 14 through the final visit (Day 56/84). Skin lesions improved significantly, with complete resolution by Day 28 and no recurrence thereafter. No treatment-related adverse events were observed. These findings indicated that fluralaner chewable tablets provided effective control of natural tick infestations and achieved complete tick-free status for 12 weeks against H. longicornis and 8 weeks against R. sanguineus under field conditions.