title: Sustained speed of kill and repellency of a novel combination of fipronil and permethrin against Ctenocephalides canis flea infestations in dogs.
abstract: BACKGROUND
  Ctenocephalides canis is a major flea species in dogs in several European countries. The new topical combination of fipronil and permethrin (Frontline Tri-Act/Frontect, Merial) has been developed to control fleas, ticks, mosquitoes, sandflies and biting flies on dogs. Considering the repellent and insecticidal effects of permethrin and the insecticidal effect of fipronil, the efficacy of the combination against fleas including C. canis was expected to be rapid. The study was conducted to measure the 1-hour, 6-hour and 24-hour efficacy, as well as the repellent activity, of the fipronil-permethrin combination on treated versus untreated dogs.
  
  
  METHODS
  12 Beagle dogs were randomly allocated to one of two groups based on pre-treatment live flea counts. Dogs in Group 1 remained untreated whereas dogs in Group 2 were treated once on Day 0. Each dog was infested with 100 unfed adult C. canis on Days 2, 7, 14, 21 and 28. Dogs were combed for fleas 1 and 6 h after each infestation. Following this examination, fleas remaining on the liner at the bottom of each cage were collected and counted. All live fleas were placed back on each dog after the 1- and 6-hour counts. A comb-count was performed at 24 h post infestation on all dogs.
  
  
  RESULTS
  Treated dogs had significantly (p ≤ 0.01) lower flea counts than untreated dogs at every time point. The percent efficacy was ≥99.1% at 6 and 24 h after each weekly challenge up to the month. The 1-hour counts also showed good efficacy of 96.5%, 98.9%, 92.0%, 70.2% and 55.7% on Days 2, 7, 14, 21 and 28, respectively. The repellent efficacy, assessed on the liners at 1 h, was 86.5%, 94.9%, 79.5%, 58.4% and 43.9% on Days 2, 7, 14, 21 and 28, respectively.
  
  
  CONCLUSIONS
  This study demonstrates the beneficial effect of the fipronil and permethrin combination against C. canis, providing both a repellent and insecticidal effect as early as 1 h post infestation, and >99.1% efficacy calculated at 6 h during a month.
authors.affiliation: Merial S.A.S., 29 Av. Tony Garnier, 69007, Lyon, France. frederic.beugnet@merial.com.
authors.forename: Frederic
authors.initials: F
authors.lastname: Beugnet
authors.affiliation: Merial S.A.S., 29 Av. Tony Garnier, 69007, Lyon, France. mark.soll@merial.com.
authors.forename: Mark
authors.initials: M
authors.lastname: Soll
authors.affiliation: Service de Parasitologie, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076, Toulouse, France. e.bouhsira@envt.fr.
authors.forename: Emilie
authors.initials: E
authors.lastname: Bouhsira
authors.affiliation: Service de Parasitologie, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076, Toulouse, France. m.franc@envt.fr.
authors.forename: Michel
authors.initials: M
authors.lastname: Franc
mesh_terms: D000287:Administration, Topical; D000818:Animals; D058251:Ctenocephalides / Q000187:drug effects* / Q000502:physiology; D004283:Dog Diseases / Q000188:drug therapy* / Q000469:parasitology; D004285:Dogs; D004341:Drug Evaluation / Q000662:veterinary; D004359:Drug Therapy, Combination / Q000662:veterinary; D005260:Female; D058267:Flea Infestations / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D007306:Insecticides / Q000008:administration & dosage*; D008297:Male; D026023:Permethrin / Q000008:administration & dosage*; D011720:Pyrazoles / Q000008:administration & dosage*
chemical_list: D007306:Insecticides; D011720:Pyrazoles; D026023:Permethrin; C082360:fipronil