title: Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations with four North American tick species (Dermacentor variabilis, Ixodes scapularis, Amblyomma americanum and Amblyomma maculatum) on dogs.
abstract: Five laboratory studies were conducted to confirm that a single topical dose of the novel combination of fipronil, amitraz and (S)-methoprene, CERTIFECT™ (Merial Limited, GA, USA), is efficacious for the rapid control of pre-existing infestations and the prevention of new infestations with Ixodes scapularis, Dermacentor variabilis, Amblyomma americanum and Amblyomma maculatum for at least 28 days on dogs. In each study, 8 male and 8 female purpose-bred, laboratory beagles were randomly assigned to one of two study groups (treated and untreated). Starting on the day before treatment, each dog was infested weekly with about 30 or 50 ticks, depending on the study. Treatment with the novel combination rapidly eliminated pre-existing infestations and controlled weekly re-infestations for at least 28 days. Pre-existing infestations with all four tick species were rapidly and effectively reduced, with post-treatment therapeutic efficacies ranging from 91.7 to 99.5% within 18-48 h post treatment. Amblyomma maculatum numbers were significantly (p<0.05) reduced on treated dogs from the first tick counts as early as 6h post-treatment. All subsequent infestations with each of the 4 tick species were quickly disrupted, with prophylactic efficacies greater than 90% within 18-48 h post-infestation for at least a full month. Because the combination of fipronil, amitraz and (S)-methoprene quickly starts disrupting and killing ixodid ticks within hours of treatment, with similar high levels of efficacy maintained for at least 28 days in these and other studies, the authors conclude that a single topical treatment with CERTIFECT may prevent the transmission of most infectious agents carried by ixodid ticks for at least one month.
authors.affiliation: Merial Limited, 115 Transtech Drive, Athens, GA, USA. christine.baker@merial.com
authors.forename: Christine F
authors.initials: CF
authors.lastname: Baker
authors.forename: James S
authors.initials: JS
authors.lastname: Hunter
authors.forename: John W
authors.initials: JW
authors.lastname: McCall
authors.forename: David R
authors.initials: DR
authors.lastname: Young
authors.forename: Jakie A
authors.initials: JA
authors.lastname: Hair
authors.forename: William R
authors.initials: WR
authors.lastname: Everett
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Yoon
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Irwin
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Young
authors.forename: Luiz G
authors.initials: LG
authors.lastname: Cramer
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Pollmeier
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Prullage
mesh_terms: D000287:Administration, Topical; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy* / Q000469:parasitology / Q000517:prevention & control; D004285:Dogs; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D007306:Insecticides / Q000494:pharmacology / Q000627:therapeutic use*; D026863:Ixodidae / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D008297:Male; D008726:Methoprene / Q000494:pharmacology / Q000627:therapeutic use; D011720:Pyrazoles / Q000494:pharmacology / Q000627:therapeutic use; D013983:Tick Control / Q000379:methods; D013984:Tick Infestations / Q000188:drug therapy / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D013997:Time Factors; D014052:Toluidines / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome; D014481:United States
chemical_list: D004338:Drug Combinations; D007306:Insecticides; D011720:Pyrazoles; D014052:Toluidines; C014983:amitraz; D008726:Methoprene; C082360:fipronil