Efficacy of orally administered fluralaner in dogs against laboratory challenge with Haemaphysalis longicornis ticks

Abstract

BackgroundHaemaphysalis longicornis ticks represent an ectoparasitic health threat to dogs. This study evaluated the immediate and persistent efficacy of orally administered fluralaner for control of this tick.MethodsTwenty-four dogs were sorted into 4 groups based on their tick carrying capacity measured in a preliminary challenge. Two days before treatment, dogs were challenged with Haemaphysalis longicornis and then at the time of treatment dogs received with oral fluralaner at 10, 25 or 50 mg/kg respectively to 3 of the groups, while the remaining group was sham treated. Ticks were counted and categorized on all dogs 2 days after treatment (4 days after challenge). Tick challenges were repeated at 28, 56, 84 and 112 days following treatment with tick counts 48 hours following each challenge. Tick control efficacy was evaluated by comparing the mean (geometric) total live attached and dead engorged ticks on each fluralaner treated group with the sham treated dogs.ResultsOral fluralaner is highly acaricidal for H. longicornis that feed on treated dogs. The mean efficacy rate in dogs treated with fluralaner at the commercial dose range of 25 to 50 mg/kg was greater than 90% at 114 days after treatment, whereas efficacy at this time in dogs treated at 10 mg/kg was 79%.ConclusionsFluralaner administered orally to dogs within the commercial dose range at 25 to 50 mg/kg is effective for up to 114 days against laboratory challenge with H. longicornis ticks.

Efficacy of sarolaner (Simparica®) against induced infestations of Haemaphysalis longicornis on dogs

“…Similar high level of efficacy could be expected against adult H. longicornis as sarolaner has demonstrated month long efficacy against the adults of many tick species globally [19–22]. Another oral isoxazoline, afoxolaner, has been evaluated against adult H. longicornis and produced efficacy > 91.9% (based on live tick counts) up to 30 days after a single treatment [24] and recently a third isoxazoline, lotilaner, provided efficacy of > 95% against adults for up to 35 days after a single oral dose [25], while a fourth, fluralaner resulted in efficacy of 93.6% or more for 114 days after the recommended dosage [26]. It should be noted that efficacy in the latter two studies was based on counts of live attached ticks only; when sarolaner was assessed using attached ticks, efficacy was 100% for the entire 35 days.…”

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

“…The finding of 100% efficacy of this oral formulation against both tested strains of H. longicornis in these two studies confirms the earlier dose-ranging study and shows that, as against other tick species, fluralaner remains highly effective for at least 12 weeks. That high fluralaner efficacy against both the recent US isolates, as well as against the Japanese strain tested in an earlier study [ 16 ], compares favorably with other investigations of isoxazolines, all requiring monthly retreatments, against H. longicornis .…”

“…When administered orally to dogs at the minimum label dose rate of 25 mg/kg, the acaricidal isoxazoline compound fluralaner has been shown to provide 8-week efficacy against Amblyomma americanum and 12-week or longer efficacy against Ixodes scapularis, Ixodes ricinus, Ixodes holocyclus, Rhipicephalus sanguineus, Dermacentor reticulatus and fleas as well as effectiveness against demodectic and sarcoptic mites [11][12][13][14][15]. A dose-ranging study conducted with a Japanese strain of H. longicornis (Okayama) indicated that that the minimum label dose rate would provide high and long-lasting efficacy against this tick for 114 days [16]. To confirm the results of that study and to establish a fluralaner claim for efficacy, laboratory studies were initiated against two different US isolates of H. longicornis.…”

Lethal and sublethal effects of fluralaner on the citrus red mite, Panonychus citri (McGregor)

“…9 Fluralaner is an isoxazoline and is a member of compound Group 30 acted as GABA-gated chloride channel allosteric modulators according to the Insecticide Resistance Action Committee (IRAC). Originally, Fluralaner was considered an ectoparasiticide 9 and subsequent studies indicate that it has broad spectrum application and high toxicity to a number of ectoparasite pests, such as Dermacentor reticulatus, 10,11 Ixodes ricinus, 12,13 Ixodes holocyclus, 14 Ornithodoros moubata, Rhipicephalus microplus, 15 Haemaphysalis longicornis, 16 Ctenocephalides felis, 17 Dermanyssus gallinae 18 and Ornithonyssus sylviarum. 19 Fluralaner is extremely effective at knocking down these ectoparasites, and is commonly sold under the name Bravecto™ for flea and tick management in animals in Europe, USA and Asia.…”