title: Efficacy of moxidectin microsphere sustained release formulation for the prevention of subcutaneous filarial (Dirofilaria repens) infection in dogs.
abstract: A study was carried out to assess the efficacy of a moxidectin microsphere sustained release (SR) injectable formulation (Guardian SR Iniettabile, Fort Dodge) for the prevention of Dirofilaria repens infection in experimentally infected dogs. On day 0, 18 Beagle dogs, 9 male dogs and 9 female dogs, weighing 12-16 kg were ranked in ascending order of body weight (b.w.) and blocked into pairs. Within each pair, dogs were allocated to Group 1 or Group 2 at random. On the same day, dogs in Group 1 were injected with 0.05 ml/kg b.w. of saline solution and dogs in Group 2 were injected with moxidectin SR at the label dose 0.17 mg/kg b.w. (0.05 ml/kg b.w.). Six months after moxidectin SR or saline injection, on day 180, each dog in the two groups was challenged with 50 infective larvae of D. repens collected from laboratory-reared, experimentally infected Aedes aegypti. Dogs were humanely euthanized on day 380 of the study, approximately 7 months from D. repens challenge. At necropsy, no worms were found in dogs treated with moxidectin SR (Group 2) while adult worms were found in saline-treated dogs (total 90; 38 males and 52 females; arithmetic mean 10, standard error 0.96, median 9, range 7-15) (Group 1 vs Group 2 P<0.001). In this experimental study, moxidectin SR injectable showed full efficacy (100%) lasting at least 6 months, and is able to prevent subcutaneous D. repens patent infection throughout the entire transmission season in Europe.
authors.affiliation: DIPAV, Università degli Studi di Milano, Via Caloria 10, 20133 Milano, Italy. marco.genchi@unimi.it
authors.forename: Marco
authors.initials: M
authors.lastname: Genchi
authors.forename: Graziano
authors.initials: G
authors.lastname: Pengo
authors.forename: Claudio
authors.initials: C
authors.lastname: Genchi
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000494:pharmacology* / Q000592:standards / Q000627:therapeutic use; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000494:pharmacology* / Q000592:standards / Q000627:therapeutic use; D004182:Dirofilaria / Q000254:growth & development*; D004184:Dirofilariasis / Q000188:drug therapy / Q000469:parasitology* / Q000517:prevention & control; D004283:Dog Diseases / Q000188:drug therapy / Q000469:parasitology* / Q000517:prevention & control; D004285:Dogs; D005260:Female; D018942:Macrolides / Q000008:administration & dosage / Q000494:pharmacology / Q000592:standards / Q000627:therapeutic use; D008297:Male; D011897:Random Allocation; D018709:Statistics, Nonparametric
chemical_list: D000871:Anthelmintics; D003692:Delayed-Action Preparations; D018942:Macrolides; C027837:moxidectin