title: Efficacy of oral afoxolaner plus milbemycin oxime chewables against induced gastrointestinal nematode infections in dogs.
abstract: The efficacy of oral afoxolaner plus milbemycin oxime combination chewables against induced gastrointestinal nematode infections in dogs was evaluated in six separate studies. Two studies were performed to evaluate the efficacy of the product against Toxocara canis, two studies evaluated the efficacy against Toxascaris leonina, one study evaluated the efficacy against Ancylostoma braziliense, and one study evaluated the efficacy against Ancylostoma caninum. In the A. caninum study, the efficacy of milbemycin oxime alone and afoxolaner alone was also evaluated. Dogs in all studies were inoculated with infective eggs or larvae and confirmed to have patent infections based on a fecal examination prior to allocation to study group and treatment. Each study utilized a randomized block design with blocks based on pre-treatment body weight. All dogs were assigned to blocks based on body weight, and then each dog within a block was randomly assigned to treatment group. There were two groups of 10 dogs each in the T. canis, T. leonina, and A. braziliense studies: 1) an untreated (control) group and 2) a group treated with afoxolaner plus milbemycin oxime chewables (NexGard Spectra(®), Merial). This group was treated at a dose as close as possible to the minimum effective dose of afoxolaner and milbemycin oxime (2.5mg+0.5mg per kg body weight, respectively) once on Day 0 using whole chews. There were four groups of 10 dogs each in the A. caninum study: 1) untreated (control), 2) NexGard Spectra(®) as described above, 3) milbemycin oxime alone (dose of at least 0.5mg per kg of body weight) and 4) afoxalaner alone (dose of at least 2.5mg per kg body weight). For parasite recovery and counts, dogs were euthanized humanely and necropsied seven days after treatment. The efficacy of the afoxolaner plus milbemycin oxime combination was ≥98% against T. canis, ≥95.8% against T. leonina, and 90.2% against A. braziliense. Efficacy of the combination against A. caninum was 99.7%, while the efficacy of milbemycin oxime alone was 99.6% and the efficacy of afoxolaner alone was 2.1%. Dogs treated with afoxolaner plus milbemycin oxime chewables had significantly (p≤0.0002) fewer nematodes than the untreated controls in all studies. There were no adverse events or other health problems that were related to treatment with Nexgard Spectra(®) in these studies. The results of these controlled studies demonstrate the high efficacy of the afoxolaner plus milbemycin oxime chewables against a broad range of canine intestinal nematode infections.
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA 30096, USA. Electronic address: becky.fankhauser@merial.com.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Fankhauser
authors.affiliation: Merial GmbH, Kathrinenhof Research Center, Walchenseestr. 8-12, 83101 Rohrdorf, Germany. Electronic address: dietmar.hamel@merial.com.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Hamel
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA 30096, USA. Electronic address: paul.dorr@merial.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Dorr
authors.affiliation: East Tennessee Clinical Research, Inc., 80 Copper Ridge Farm Road, Rockwood, TN 37854, USA. Electronic address: crr@easttenncr.com.
authors.forename: Craig R
authors.initials: CR
authors.lastname: Reinemeyer
authors.affiliation: ClinVet International (Pty) Ltd., Uitsig Road, Bainsvlei, 9321 Bloemfontein, South Africa; University of Johannesburg, Department of Zoology, c/o Kingsway and University Road, Aucklandpark, Johannesburg, South Africa. Electronic address: dionne.crafford@clinvet.com.
authors.forename: Dionne
authors.initials: D
authors.lastname: Crafford
authors.affiliation: Cheri-Hill Kennel & Supply, Inc., 17190 Polk Road, Stanwood, MI 49346, USA. Electronic address: dbb3@cornell.edu.
authors.forename: Dwight D
authors.initials: DD
authors.lastname: Bowman
authors.affiliation: Cheri-Hill Kennel & Supply, Inc., 17190 Polk Road, Stanwood, MI 49346, USA. Electronic address: misiu@frontier.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Ulrich
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA 30096, USA. Electronic address: stephen.yoon@merial.com.
authors.forename: Stephen
authors.initials: S
authors.lastname: Yoon
authors.affiliation: Merial, Inc., 3239 Satellite Blvd., Duluth, GA 30096, USA. Electronic address: diane.larsen@merial.com.
authors.forename: Diane L
authors.initials: DL
authors.lastname: Larsen
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004338:Drug Combinations; D007555:Isoxazoles / Q000008:administration & dosage*; D018942:Macrolides / Q000008:administration & dosage*; D009281:Naphthalenes / Q000008:administration & dosage*; D009349:Nematode Infections / Q000188:drug therapy / Q000662:veterinary*; D011897:Random Allocation; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; D007555:Isoxazoles; D018942:Macrolides; D009281:Naphthalenes; C000589002:afoxolaner; C078973:milbemycin oxime
keywords: Afoxolaner; Ancylostoma braziliense; Ancylostoma caninum; Dog; Milbemycin oxime; Toxascaris leonina; Toxocara canis