title: A field trial of spinosad for the treatment and prevention of flea infestation in shepherd dogs living in close proximity to flea-infested sheep.
abstract: BACKGROUND
  Three flea species, Pulex irritans, Ctenocephalides canis and C. felis parasitize shepherd dogs living on sheep farms in Greece. The aim of this randomized, blinded, placebo-controlled trial was to examine the efficacy of spinosad, when administered three times every 4 weeks, as the only intervention to treat and prevent flea infestations in shepherd dogs living on sheep farms.
  
  
  METHODS
  Thirty dogs living on sheep farms and infested by at least 24 fleas were randomly allocated into equal groups. Group A dogs received spinosad (45-70 mg/kg body weight), every 4 weeks for three administrations, whereas Group B dogs were placebo-treated. Flea counting was performed at the beginning of the trial (day 0) and after 14, 28, 56 and 84 days. The first five fleas from each dog and 2-6 fleas collected from 5-11 sheep were used for species identification.
  
  
  RESULTS
  The percentage of dogs with zero flea counts was significantly higher in group A than in group B at days 14, 28, 56 and 84 and flea counts were significantly lower in group A than in group B at days 14, 28, 56 and 84. In group A, flea counts were significantly lower at days 14, 28, 56 and 84 compared to day 0 whereas there were no changes in flea counts of group B dogs. The percent efficacy of spinosad for the treatment and prevention of flea infestation was higher than 98% (arithmetic means) or higher than 99% (geometric means) throughout the study. No adverse reactions were recorded. C. canis was the predominant flea species of dogs at day 0. In group A the relative abundance of C. felis increased at day14 whereas in group B the relative abundance of P. irritans increased at days 14, 28, 56 and 84.
  
  
  CONCLUSIONS
  Spinosad is safe and effective for the treatment of C. canis and C. felis infestations and for the prevention of P. irritans, C. canis and C. felis infestations in shepherd dogs living in close proximity to sheep.
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece. msarido@vet.uth.gr.
authors.forename: Manolis N
authors.initials: MN
authors.lastname: Saridomichelakis
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece. mchatzis@vet.uth.gr.
authors.forename: Manolis K
authors.initials: MK
authors.lastname: Chatzis
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Science, University of Thessaly, 224 Trikalon Str., GR-43100, Karditsa, Greece. tpetanid@gmail.com.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Petanides
authors.affiliation: Laboratory of Parasitology and Parasitic Diseases, Faculty of Veterinary Sciences, Aristotle University of Thessaloniki, University Campus, GR-54124, Thessaloniki, Greece. eliaspap@vet.auth.gr.
authors.forename: Elias
authors.initials: E
authors.lastname: Papadopoulos
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000469:parasitology / Q000517:prevention & control*; D004285:Dogs; D004338:Drug Combinations; D005260:Female; D058267:Flea Infestations / Q000469:parasitology / Q000662:veterinary*; D007300:Insect Control; D007306:Insecticides / Q000008:administration & dosage*; D018942:Macrolides / Q000008:administration & dosage*; D008297:Male; D010270:Parasite Egg Count; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology*; D005423:Siphonaptera / Q000187:drug effects / Q000502:physiology
chemical_list: D004338:Drug Combinations; D007306:Insecticides; D018942:Macrolides; C415329:spinosad