title: The efficacy of a topically applied imidacloprid 10 % / moxidectin 2.5 % formulation (Advocate®, Advantage® Multi, Bayer) against Immature and Adult Spirocerca lupi worms in experimentally infected dogs.
abstract: This study investigated the efficacy and safety of an imidacloprid 10 %/moxidectin 2.5 % spot-on combination (Advocate®, Advantage® Multi, Bayer) against immature and mature stages of Spirocerca lupi in experimentally infected dogs. 24 dogs were allocated to 3 groups and infected with approximately 10 L3 larvae of S. lupi orally on study day (SD) +2, +14, +28 and +42. Group 1 remained as untreated control group. Group 2 dogs were treated on SD –28, 0, and thereafter monthly until Day 280 (12 treatments). Group 3 dogs were treated weekly on 19 occasions starting on SD +170. The dosage for all treatments was the licensed dose of 10–25 mg imidacloprid/2.5–6.25 mg moxidectin per kg body weight. All dogs were examined on SD +169 or +176 by endoscopy. Group 3 dogs were additionally examined approximately every two weeks up to Day 296. On Day +308 or +310, all dogs were necropsied to recover S. lupi worms and to quantify lesions in the thoracic aorta and oesophagus. Dogs in the control group were adequately infected with S. lupi, demonstrated by the extensive damage to the thoracic aorta, the nodules in the oesophagus and the large numbers of worms recovered. In total 144 worms were collected (geometric mean of 16.8 worms per dog). Dogs in group 2 had no or very slight damage to the thoracic aorta and no nodules or worms in the oesophagus, indicating 100 % efficacy of the monthly treatments. Dogs in group 3 were also adequately infected, showing nodules in the oesophagus before initiation of weekly treatment, and at necropsy extensive damage was seen in the thoracic aorta. After treatment, three dogs of 8 still had a few nodules and in total three worms (GM of 0.25 per dog) were recovered, demonstrating an efficacy of 98.5 % against adult S. lupi. All dogs tolerated the treatment well and no treatment- related adverse events occurred.
authors.affiliation: Bayer (Pty) Ltd, Isando, South Africa.
authors.forename: Clinton M
authors.initials: CM
authors.lastname: Austin
authors.forename: Dawie J
authors.initials: DJ
authors.lastname: Kok
authors.forename: Dionne
authors.initials: D
authors.lastname: Crafford
authors.forename: Roland
authors.initials: R
authors.lastname: Schaper
mesh_terms: D000328:Adult; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage* / Q000009:adverse effects; D001013:Aorta, Thoracic / Q000469:parasitology / Q000473:pathology; D004195:Disease Models, Animal; D004285:Dogs; D004338:Drug Combinations; D004724:Endoscopy; D004947:Esophagus / Q000469:parasitology / Q000473:pathology; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage* / Q000009:adverse effects; D018942:Macrolides / Q000008:administration & dosage* / Q000009:adverse effects; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000008:administration & dosage* / Q000009:adverse effects; D017205:Spirurida Infections / Q000188:drug therapy* / Q000469:parasitology*; D013802:Thelazioidea / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000871:Anthelmintics; D004338:Drug Combinations; D007093:Imidazoles; D018942:Macrolides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid; C027837:moxidectin