title: Onset of activity of fluralaner (BRAVECTO™) against Ctenocephalides felis on dogs.
abstract: BACKGROUND
  Fluralaner (Bravecto™) is a novel systemic insecticide and acaricide that provides long persistent antiparasitic activity following a single administration at the minimum dose of 25 mg/kg body weight.
  
  
  METHODS
  Three negative controlled, randomized studies were conducted in dogs to evaluate the start to kill (1 study) and the speed of flea kill (2 studies) of fluralaner. All dogs were infested prior to treatment with unfed adult C. felis fleas. Dogs in the treated groups were administered once orally with fluralaner at a minimum dose of 25 mg/kg body weight, while dogs in the control groups were not treated. Separate control and treatment groups were paired at each time point of flea assessment. Flea counts were performed by combing dogs at either 0.5, 1, 2, or 4 hours after fluralaner treatment to measure the start to kill. To evaluate the speed of flea kill over 12 weeks, flea counts were performed by combing dogs at either 4, 8, 12, or 24 hours after fluralaner treatment and then at 4, 8, 12, or 24 hours after each flea re-infestations performed at 4, 8, and 12 weeks following treatment.
  
  
  RESULTS
  In the start to kill study, the fluralaner activity against fleas started already at 1 hour post-treatment (8% numerical efficacy). At 2 and 4 hours post-treatment, the flea reduction was significant with 36.7% and 88% efficacy, respectively. In the speed of kill studies, the efficacy against fleas after fluralaner treatment was 80.5% at 4 hours and remained ≥ 99.4% at 8, 12 and 24 hours. After flea re-infestations in weeks 4, 8 and 12, the efficacy at 4 hours was 96.8, 91.4, and 33.5%, respectively. Efficacy at 8, 12 and 24 hours after flea re-infestations was 98.0-100% for the 12 weeks of the study. Except for 4 hours after the 12-week flea re-infestation, flea reduction was significant for all time points after flea re-infestation.
  
  
  CONCLUSIONS
  Single oral fluralaner administration rapidly eliminates existing flea infestations and provides excellent protection against fleas over 12 weeks following treatment.
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. janina.taenzler@msd.de.
authors.forename: Janina
authors.initials: J
authors.lastname: Taenzler
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. christina.wengenmayer@msd.de.
authors.forename: Christina
authors.initials: C
authors.lastname: Wengenmayer
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. heike.williams@msd.de.
authors.forename: Heike
authors.initials: H
authors.lastname: Williams
authors.affiliation: ClinVet International, Uitsigweg, Bainsvlei, 9338, Bloemfontein, Free State, South Africa. josephus.fourie@clinvet.com.
authors.forename: Josephus
authors.initials: J
authors.lastname: Fourie
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. eva.zschiesche@msd.de.
authors.forename: Eva
authors.initials: E
authors.lastname: Zschiesche
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. rainer.roepke@msd.de.
authors.forename: Rainer K A
authors.initials: RK
authors.lastname: Roepke
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany. anja.heckeroth@msd.de.
authors.forename: Anja R
authors.initials: AR
authors.lastname: Heckeroth
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D058267:Flea Infestations / Q000188:drug therapy / Q000662:veterinary*; D007306:Insecticides / Q000008:administration & dosage / Q000627:therapeutic use*; D007555:Isoxazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male
chemical_list: C000591860:A1443 compound; D007306:Insecticides; D007555:Isoxazoles