title: Urinary oxytocin as a noninvasive biomarker of positive emotion in dogs.
abstract: A reliable assay based on physiological parameters that does not require subjective input from the owners is required to assess positive emotions in dogs. In addition, when viewed from an animal welfare perspective, physiological parameters should be collected in a noninvasive manner. Oxytocin (OT) is a biomarker that may be associated with a calm, relaxed state, and positive emotion. We measured the time-lapse in the concentration of plasma OT relative to urinary OT using a radioimmunoassay with sufficient sensitivity and low variability, and examined the relationship between OT and cortisol. Six dogs were injected with exogenous OT intravenously to increase the blood OT concentration. As a result, the highest concentration of urinary OT occurred 1h after the injection, although there was little change in urinary cortisol. Moreover, to evaluate the influence of stimuli on urinary OT and cortisol, we provided three stimuli of eating food, exercising and stroking, all of which were assumed to inspire a positive emotion in dogs, and significantly increased urinary OT concentrations. Our findings indicate that urinary OT might be useful as a noninvasive and objective biomarker of positive emotion in dogs.
authors.affiliation: Department of Animal Science and Biotechnology, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan. kuryuusinnkai@gmail.com
authors.forename: Shohei
authors.initials: S
authors.lastname: Mitsui
authors.forename: Mariko
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Miho
authors.initials: M
authors.lastname: Nagasawa
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Mogi
authors.forename: Takefumi
authors.initials: T
authors.lastname: Kikusui
authors.forename: Nobuyo
authors.initials: N
authors.lastname: Ohtani
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ohta
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D015415:Biomarkers / Q000652:urine; D004285:Dogs; D004435:Eating / Q000523:psychology; D004644:Emotions; D006854:Hydrocortisone / Q000652:urine; D008297:Male; D008405:Massage / Q000523:psychology; D010121:Oxytocin / Q000008:administration & dosage / Q000097:blood / Q000652:urine*; D010805:Physical Conditioning, Animal / Q000523:psychology
chemical_list: D015415:Biomarkers; D010121:Oxytocin; D006854:Hydrocortisone