title: Efficacy of oral afoxolaner plus milbemycin oxime chewables against induced infestations with Dermacentor reticulatus in dogs.
abstract: The efficacy of afoxolaner plus milbemycin oxime (AFX + MO) combination chewables (NexGard Spectra®, Merial) and AFX single-entity chewables (NexGard®, Merial) against induced infestations with Dermacentor reticulatus ticks was evaluated in dogs. Thirty dogs were assigned to blocks of three animals each based on pre-allocation tick counts and were randomly allocated to one of three groups: untreated (control), treated with a combination of AFX + MO chewables to be as close as possible to the minimum effective dose of AFX + MO (2.5 + 0.5 mg per kg body weight), and treated with a combination of NexGard® chewables to be as close as possible to the minimum effective dose of AFX (2.5 mg per kg body weight). Treatments were administered orally once on day 0. Starting 2 days before treatment administration, each dog was infested with approximately 50 ticks weekly for six consecutive weeks. Live ticks were counted at ∼48 h post-treatment (removal count) and at ∼48 h (in situ counts) and ∼72 h (removal counts) following each post-treatment infestation. Treatment with both AFX + MO and NexGard® chewables rapidly eliminated the existing tick infestations (100 % efficacy) within 2 days following treatment administration. Weekly re-infestations were controlled for a minimum of 5 weeks with the efficacy ranging from 92.2 to 99.7 % based on ∼48 h post-treatment in situ counts and between 99.0 and 100 % based on ∼72 h post-treatment removal counts (p < 0.0001 at each occasion). This study demonstrated a high efficacy of both AFX + MO chewable and NexGard® chewable treatments against infestations of dogs with D. reticulatus ticks for at least 5 weeks. In addition, this study indicated no interference between the two compounds with respect to the acaricidal activity provided by AFX.
authors.affiliation: Merial GmbH, Kathrinenhof Research Center, Walchenseestr. 8-12, 83101, Rohrdorf, Germany. steffen.rehbein@merial.com.
authors.forename: Steffen
authors.initials: S
authors.lastname: Rehbein
authors.affiliation: ClinVet International (Pty) Ltd., Uitsig Road, Bainsvlei, 9321, Bloemfontein, Republic of South Africa.
authors.forename: Josephus J
authors.initials: JJ
authors.lastname: Fourie
authors.affiliation: ClinVet International (Pty) Ltd., Uitsig Road, Bainsvlei, 9321, Bloemfontein, Republic of South Africa.
authors.forename: Christa
authors.initials: C
authors.lastname: de Vos
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA, 30096, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Anderson
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA, 30096, USA.
authors.forename: Diane L
authors.initials: DL
authors.lastname: Larsen
authors.affiliation: Merial S.A.S., Centre de Recherche de Saint-Vulbas, 1 allée des Cyprès, 01150, Saint-Vulbas, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jeannin
mesh_terms: D056810:Acaricides / Q000494:pharmacology; D000284:Administration, Oral; D000818:Animals; D003870:Dermacentor / Q000187:drug effects*; D004283:Dog Diseases / Q000188:drug therapy / Q000469:parasitology*; D004285:Dogs; D004338:Drug Combinations; D007555:Isoxazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D018942:Macrolides / Q000008:administration & dosage / Q000627:therapeutic use*; D009281:Naphthalenes / Q000008:administration & dosage / Q000627:therapeutic use*; D013984:Tick Infestations / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome
chemical_list: D056810:Acaricides; D004338:Drug Combinations; D007555:Isoxazoles; D018942:Macrolides; D009281:Naphthalenes; C000589002:afoxolaner; C078973:milbemycin oxime
keywords: Afoxolaner; Dermacentor reticulatus; Dog; Milbemycin oxime; Tick
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