A randomized controlled trial of the efficacy of orally administered fluralaner (Bravecto™) against induced Ixodes holocyclus (Australian paralysis tick) infestations on dogs

Background: ixodes holocyclus ticks are a frequently fatal threat to dogs in eastern australia. these ticks secrete a neurotoxin that can produce an ascending paralysis after 72 h attachment that can lead to death in affected animals. fluralaner is a potent systemic acaricide with immediate and persistent efficacy for tick control including evidence of 100% efficacy against ixodes ricinus ticks within 72 h. this study investigated the potential for oral fluralaner administration to control i. holocyclus infestation and the subsequent risk of host paralysis. methods: healthy foxhound and foxhound cross dogs immunized against holocyclotoxin were randomly allocated to receive either a single fluralaner (at least 25 mg/kg) dose or no treatment. all dogs were penned individually and infested with 30 adult unfed female i. holocyclus 1 day before treatment and 14,28,42,56,70,84,112 and 140 days following treatment. ticks were counted and assessed at 24,48 and 72 h after the initial fluralaner treatment and after each subsequent infestation. ticks were not removed at the 24 and 48 h assessments,but were removed after the 72 h assessments. on 112 and 140 days post treatment a new group of untreated control dogs was used. results: fluralaner treatment efficacy against i. holocyclus was 100% at 72 h post treatment. following re-infestations the efficacy remained at 100% at the 72 h assessments for 115 days and reached 95.7% at 143 days. the differences between mean live tick counts on treatment and control groups were significant (p∈<∈0.00l) at all assessment time points for 143 days following treatment. conclusions: oral fluralaner treatment can prevent australian paralysis tick infestations for at least 115 days. © 2015 fisara and webster; licensee biomed central.