title: Evaluation of the speed of kill, effects on reproduction, and effectiveness in a simulated infested-home environment of sarolaner (Simparica™) against fleas on dogs.
abstract: Four studies were conducted to evaluate the speed of kill, effect on egg production, and efficacy in a simulated infested-home environment of a novel isoxazoline, sarolaner (Simparica™, Zoetis), against fleas on dogs. Individually identified and housed, purpose-bred Beagles were used in each study and were allocated randomly to groups based on pretreatment parasite counts. In two speed of kill studies, groups of dogs infested with 100 fleas prior to treatment were treated orally with placebo or sarolaner tablets providing the minimum dose of 2mg/kg and then re-infested with fleas weekly for five weeks post-treatment. Comb counts were conducted to determine the numbers of viable fleas at one to three, four, eight and 12h after treatment and each subsequent infestation. In the egg production study, sarolaner- and placebo-treated dogs were similarly challenged with fleas and at 48h after each infestation the dogs were housed for 20h in cages allowing the collection and counting of all flea eggs produced during this period. Collected eggs were incubated to evaluate hatch and development to adults. The last study used dogs housed in a flea-infested simulated-home environment. Dogs were allocated to treatment with either placebo or sarolaner tablets providing a dose of 2mg/kg once a month for three treatments. Flea infestations were assessed by comb counts (fleas were replaced on the dogs) on Days 14, 30, 44, 60, 74 and 90. The speed of kill studies demonstrated that a single 2mg/kg oral dose of sarolaner started killing fleas within three to four hours after treatment or subsequent re-infestations for up to a month, and achieved ≥98% control of fleas by eight hours after treatment or re-infestation for 28 days. In the study to assess effects on flea reproduction, a single oral treatment of sarolaner resulted in the complete cessation of egg-laying for 35 days. This rapid kill of fleas and inhibition of reproduction were confirmed in a simulated-home environment where the existing infestations were reduced by >95% within two weeks of the first treatment and eliminated from the dogs after two monthly doses.
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, 333 Portage St., Kalamazoo, MI 49007, USA. Electronic address: robert.six@Zoetis.com.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Six
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, Hoge Wei 10, B-1930 Zaventem, Belgium.
authors.forename: Csilla
authors.initials: C
authors.lastname: Becskei
authors.affiliation: Stillmeadow Inc., 12852 Park One Drive, Sugar Land, TX 77478, USA.
authors.forename: Lori
authors.initials: L
authors.lastname: Carter
authors.affiliation: Charles River Laboratories, Pre-Clinical Services, Glenamoy Co., Mayo, Ireland.
authors.forename: Boyd
authors.initials: B
authors.lastname: Gale
authors.affiliation: YVRS, 7243 East Ave, Turlock, CA 95380, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Young
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, 333 Portage St., Kalamazoo, MI 49007, USA.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Mahabir
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, 333 Portage St., Kalamazoo, MI 49007, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Chapin
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, 333 Portage St., Kalamazoo, MI 49007, USA.
authors.forename: Melanie R
authors.initials: MR
authors.lastname: Myers
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D058267:Flea Infestations / Q000188:drug therapy / Q000662:veterinary*; D007306:Insecticides / Q000494:pharmacology / Q000592:standards / Q000627:therapeutic use; D007555:Isoxazoles / Q000494:pharmacology* / Q000592:standards / Q000627:therapeutic use; D012098:Reproduction / Q000187:drug effects; D005423:Siphonaptera / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D007306:Insecticides; D007555:Isoxazoles
keywords: Ctenocephalides felis felis; Dog; Efficacy; Environmental; Flea; Isoxazoline; Oral; Reproduction; Sarolaner; Simparica™; Speed of kill