title: Comparative speed of kill after treatment with Simparica™ (sarolaner) and Advantix®(imidacloprid + permethrin) against induced infestations of Dermacentor reticulatus on dogs.
abstract: BACKGROUND
  Ticks are common ectoparasites that infest dogs globally. Acaricides with rapid and sustained speed of kill are critical to control infestations and to reduce the risk of disease transmission. This study evaluated the speed of kill for 5 weeks after a single dose of orally administered Simparica™ (sarolaner) against induced infestations with Dermacentor reticulatus on dogs, compared to Advantix® Spot-on solution for dogs (imidacloprid + permethrin).
  
  
  METHODS
  Twenty four dogs were randomly allocated to treatment with either a placebo tablet, a sarolaner tablet (at 2 to 4 mg/kg) or with Advantix® as per label instructions. Dogs were treated on Day 0 and tick counts were performed in situ at 8 and 12 hours and with removal of the ticks at 24 hours after treatment and subsequent re-infestations on Days 7, 14, 21, 28 and 35. Acaricidal efficacy was determined at each time point relative to live tick counts from the placebo-treated dogs.
  
  
  RESULTS
  Based on arithmetic (geometric) mean tick counts, the efficacy of sarolaner was ≥75.6 % (89.6 %) within 8 hours of treatment and tick counts were significantly lower than placebo and imidacloprid + permethrin-treated dogs (P < 0.0001), while imidacloprid + permethrin had no significant reduction (P ≥ 0.3990) at 8 or 12 hours after treatment. Sarolaner killed all ticks on the dogs within 24 hours after treatment, while imidacloprid + permethrin efficacy was only 48.1 %. After weekly re-infestations sarolaner significantly reduced the tick counts versus placebo within 8 hours on Days 7, 14 and 35 (P ≤ 0.0239), and at 12 hours and 24 hours (P ≤ 0.0079) until Day 35.Sarolaner efficacy was ≥95.8 % within 24 hours for 35 days. Significantly more live ticks (P ≤ 0.0451) were recovered from imidacloprid + permethrin-treated dogs than from sarolaner-treated dogs at 24 hours after infestation on all days. There were no sarolaner-related adverse reactions during the study.
  
  
  CONCLUSIONS
  This study demonstrated that Simparica™ had a faster and more consistent speed of kill against D. reticulatus compared to Advantix®. The rapid and consistent efficacy within 24 hours for 5 weeks after a single oral dose of Simparica™ provides effective and reliable control of D. reticulatus and reduces the risk of transmission of tick-borne diseases.
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, Mercuriusstraat 20, Zaventem, B-1930, Belgium. csilla.becskei@zoetis.com.
authors.forename: Csilla
authors.initials: C
authors.lastname: Becskei
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, Mercuriusstraat 20, Zaventem, B-1930, Belgium. thomas.geurden@zoetis.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Geurden
authors.affiliation: ClinVet International (pty) Ltd, Uitsigweg, Bainsvlei 9338, Bloemfontein, Republic of South Africa. heidi.erasmus@clinvet.com.
authors.forename: Heidi
authors.initials: H
authors.lastname: Erasmus
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, Mercuriusstraat 20, Zaventem, B-1930, Belgium. otto.cuppens@zoetis.com.
authors.forename: Otto
authors.initials: O
authors.lastname: Cuppens
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, 333 Portage St., Kalamazoo, MI, 49007, USA. sean.mahabir@zoetis.com.
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. robert.six@zoetis.com.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Six
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003870:Dermacentor / Q000187:drug effects* / Q000502:physiology; D004283:Dog Diseases / Q000188:drug therapy* / Q000469:parasitology*; D004285:Dogs; D007093:Imidazoles / Q000008:administration & dosage*; D007306:Insecticides / Q000008:administration & dosage*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000008:administration & dosage*; D026023:Permethrin / Q000008:administration & dosage*; D010919:Placebos / Q000008:administration & dosage; D011897:Random Allocation; D016019:Survival Analysis; D013984:Tick Infestations / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010919:Placebos; C082359:imidacloprid; D026023:Permethrin