Journal Article

Efficacy of fluralaner chewable tablets (Bravecto®) against Asian longhorned tick (Haemaphysalislongicornis) infestations of dogs

Liebenberg, Julian E., Petersen, Melissa, Maree, Riaan, Guerino, Frank, Viljoen, Alta

2023

Overview

Background The parthenogenic reproductive ability of Haemaphysalis longicornis , facilitating quick life cycle completion and rapid geographic spread and its pathogen vector potential make infestations a risk to human and canine health. Two 90-day studies were initiated to evaluate the efficacy of a single fluralaner administration for the treatment and prevention of H. longicornis infestations on dogs. Methods Dogs were randomly assigned (10 dogs/group) to either an untreated control group or a group treated once (Day 0) with 13.64% w/w fluralaner chewable tablets (Bravecto ® ) at the minimum label dose rate of 25 mg/kg. Each dog was infested with approximately 50 H. longicornis ticks on Days -9 or -6 and on Days -2, 28, 58 and 88. A different US tick isolate was used in each study. Tick counts were completed on Days -7 or -4, 2, 30, 60 and 90. The primary efficacy criterion was a 90% reduction in arithmetic mean tick counts between the treated and control groups. For between-group comparisons at any assessment, at least six control dogs were required to retain at least 25% of the infestation dose (13 live ticks). Results Pre-study infestations demonstrated susceptibility of all study dogs to challenge with H. longicornis . At each subsequent assessment in both studies, at least seven untreated control dogs retained ≥ 25% of the challenge, demonstrating adequate infestations for each efficacy calculation. On Days 2, 30, 60 and 90 the mean live tick infestation rate (number of ticks recovered from each dog/infesting challenge of each dog) of untreated control dogs ranged from 27.8 to 60.8%. No live ticks, free or attached, were found on any fluralaner-treated dog in either study. Between-group differences were statistically significant ( P  ≤ 0.0002) at each assessment. Conclusion At the minimum recommended label dose rate of 25 mg/kg, fluralaner chewable tablets were 100% effective in eliminating H. longicornis ticks from dogs infested at the time of treatment. Complete efficacy against both US isolates of this tick was maintained through 90 days following a single treatment. Therefore, fluralaner is a treatment of choice for protecting dogs against this invasive tick species. Graphical abstract

• Publisher: BioMed Central,Springer Nature B.V,BMC
• Subject: Acaricides - pharmacology / Acaricides - therapeutic use / Administration, Oral / Animals / Arachnids / Asian longhorned tick / Biomedical and Life Sciences / Biomedicine / Bravecto / Dog / Dog Diseases - drug therapy / Dog Diseases - prevention & control / Dogs / Dosage / Effectiveness / Efficacy / Entomology / Fluralaner chewable / Haemaphysalis longicornis / Humans / Infectious Diseases / Infestation / Introduced species / Invasive species / Ixodidae / Laboratories / Life cycle / Life cycles / Parasitology / Pathogens / reproductive performance / risk / species / Statistical analysis / Tablets / Tablets - therapeutic use / tick infestations / Tick Infestations - drug therapy / Tick Infestations - prevention & control / Tick Infestations - veterinary / Ticks / Treatment Outcome / Tropical Medicine / Vector potentials / Veterinary Medicine/Veterinary Science / Virology