Abstract
BackgroundThe lone star tick, Amblyomma americanum, infests dogs and cats in North America and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans. A parasiticide’s speed of kill is important to minimize the direct and deleterious effects of tick infestation and especially to reduce the risk of transmission of tick-borne pathogens. In this study, speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (Simparica™ chewable tablets), against A. americanum on dogs was evaluated and compared with afoxolaner (NexGard®) for 5 weeks following a single oral dose.MethodsBased on pretreatment tick counts, 24 dogs were randomly allocated to treatment with sarolaner (2 to 4 mg/kg), afoxolaner (2.5 to 6.8 mg/kg) or a placebo. Dogs were examined and live ticks counted at 8, 12, and 24 h after treatment and subsequent re-infestations on Days 7, 14, 21, 28, and 35. Efficacy was determined at each time point relative to counts for placebo dogs.ResultsA single oral dose of sarolaner provided 100 % efficacy within 24 h of treatment, and consistently provided >90 % efficacy against subsequent weekly re-infestations with ticks to Day 28. Significantly more live ticks were recovered from afoxolaner-treated dogs than from sarolaner-treated dogs at 24 h after infestation from Day 7 through Day 35 (P ≤ 0.0247). At 24 h, efficacy of afoxolaner declined to less than 90 % from Day 14 to the end of the study. There were no adverse reactions to treatment.ConclusionsIn this controlled laboratory evaluation, sarolaner had a faster speed of kill against A. americanum ticks than afoxolaner. The rapid and consistent kill of ticks by sarolaner within 24 h after a single oral dose over 28 days, suggests this treatment will provide highly effective and reliable control of ticks over the entire treatment interval, and could help reduce the risk of transmission of tick-borne pathogens by A. americanum.
Highlights
The lone star tick, Amblyomma americanum, infests dogs and cats in North America and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans
Study procedures were in accordance with the World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of parasiticides for the treatment, prevention and control of flea and tick infestation on dogs and cats [15], and complied with the principles of Good Clinical Practices [16]
Each dog was individually identified by a unique ear tattoo or electronic transponder and had undergone an adequate wash-out period to ensure that no residual ectoparasiticide efficacy remained from any previously administered treatments
Summary
The lone star tick, Amblyomma americanum, infests dogs and cats in North America and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans. A parasiticide’s speed of kill is important to minimize the direct and deleterious effects of tick infestation and especially to reduce the risk of transmission of tick-borne pathogens. The lone star tick, Amblyomma americanum, is the vector of Ehrlichia chaffeensis and Ehrlichia ewingii [3, 4], to dogs and man, which cause monocytic and granulocytic ehrlichiosis, respectively. Amblyomma americanum is one of the most common tick species infesting dogs and cats in North America. Focal populations have been reported in northern states including Maine, New York, Massachusetts, Connecticut, and New Jersey [6, 7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
