title: Quantification of brown dog tick repellents, 2-hexanone and benzaldehyde, and release from tick-resistant beagles, Canis lupus familiaris.
abstract: We have recently shown that repellency of the tick Rhipicephalus sanguineus sensu lato by the tick resistant dog breed, the beagle, is mediated by volatile organic compounds (VOCs) 2-hexanone and benzaldehyde present in beagle odour. Ectoparasite location of animal hosts is affected by variation in these odour components and their ratios. The aim of this study was to quantify the release rate, and the ratio, of 2-hexanone and benzaldehyde from beagles. The odour of three beagles was collected, for four days, over one week (day 0, day 1, day 4 and day 7). The compounds were identified using coupled high-resolution gas chromatography-mass spectrometry (GC-MS), and authentic standards of compounds were used to generate external calibration curves for quantification. Both compounds were found in all dogs on all days. The amount of benzaldehyde was always higher than that of 2-hexanone and so their ratio varied from unity, on average (over time) being 3.128±0.365, 1.902±0.390, 1.670±0.671ngmL(-1) for beagle 1, 2 and 3, respectively. There was no significant (p<0.05, F-test) effect of time. The overall mean was 2.233±0.387ngmL(-1). These results further previous findings by documenting the presence of 2-hexanone and benzaldehyde in beagle odour samples covering a 7-day period. This knowledge enables development of repellents to protect dogs from R. sanguineus s. l. infestation.
authors.affiliation: Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Campus II, Samambaia, Cx. Postal 131, Goiânia, Goiás CEP: 74001-970, Brazil. Electronic address: jaires_filho@hotmail.com.
authors.forename: Jaires Gomes
authors.initials: JG
authors.lastname: de Oliveira Filho
authors.affiliation: Biological Chemistry and Crop Protection Department, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: andre.sarria@rothamsted.ac.uk.
authors.forename: André Lucio Franceschini
authors.initials: ALF
authors.lastname: Sarria
authors.affiliation: Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Campus II, Samambaia, Cx. Postal 131, Goiânia, Goiás CEP: 74001-970, Brazil. Electronic address: loren4_lopes@hotmail.com.
authors.forename: Lorena Lopes
authors.initials: LL
authors.lastname: Ferreira
authors.affiliation: Biological Chemistry and Crop Protection Department, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: john.caulfield@rothamsted.ac.uk.
authors.forename: John C
authors.initials: JC
authors.lastname: Caulfield
authors.affiliation: Computational and Systems Biology Department, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: stephen.powers@rothamsted.ac.uk.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Powers
authors.affiliation: Biological Chemistry and Crop Protection Department, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: john.pickett@rothamsted.ac.uk.
authors.forename: John A
authors.initials: JA
authors.lastname: Pickett
authors.affiliation: USDA-ARS, Knipling-Bushland U.S. Livestock Insects Research Laboratory, Veterinary Pest Genomics Center, 2700 Fredericksburg Road, Kerrville, TX 78028, USA. Electronic address: beto.perezdeleon@ars.usda.gov.
authors.forename: Adalberto A Pérez
authors.initials: AAP
authors.lastname: de León
authors.affiliation: Biological Chemistry and Crop Protection Department, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: mike.birkett@rothamsted.ac.uk.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Birkett
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Rua 235 s/n, Setor Universitário, Goiânia, Goiás CEP: 74605050, Brazil. Electronic address: borges.ligia@gmail.com.
authors.forename: Lígia Miranda Ferreira
authors.initials: LMF
authors.lastname: Borges
mesh_terms: D000818:Animals; D001547:Benzaldehydes / Q000032:analysis* / Q000494:pharmacology*; D004285:Dogs / Q000469:parasitology*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D016014:Linear Models; D008742:Methyl n-Butyl Ketone / Q000032:analysis* / Q000494:pharmacology*; D015203:Reproducibility of Results; D048508:Rhipicephalus sanguineus / Q000187:drug effects*
chemical_list: D001547:Benzaldehydes; D008742:Methyl n-Butyl Ketone; C032175:benzaldehyde
keywords: 2-Hexanone; Benzaldehyde; GC–MS; Non-host; Rhipicephalus sanguineus sensu lato; VOC’s