title: Autonomic, endocrine and behavioural responses to thunder in laboratory and companion dogs.
abstract: Dogs are highly sensitive to sound stimuli, especially fireworks, firearms, and thunder, and therefore these sounds are used as models of stress reactivity in dogs. Companion and laboratory dogs may respond differently to stressful stimuli, due to differences in management and their relationship with humans. Therefore, the reactivity of beagle dogs (laboratory) and companion dogs to an acute acoustic stress model was studied by analysing the heart rate variability (HRV; cardiac interval values), serum cortisol levels and various behavioural parameters. Eight beagles and six privately owned dogs with no history of phobia to thunder were used. The sound stimulus consisted of a standardized recording of thunder for 2.5min with a maximum intensity of 103-104dB. To evaluate the HRV, cardiac intervals were recorded using a frequency meter (Polar RS800CX model), and later the data were analysed using CardioSeries 2.4.1 software. In both laboratory and companion dogs, thunder promoted an increase in the power of the LF band of the cardiac interval spectrum, in the LF/HF ratio and in the HR, and a decrease in the power of the HF band of the cardiac interval spectrum. Companion dogs showed higher cortisol levels, than beagles, independently of the time point studied and a significant increase in the cortisol levels 15min after acoustic stress, while beagles did not show any alterations in their cortisol levels in response to the sound. On the other hand, beagles showed higher scores in the trembling, hiding, vigilance, running, salivation, bolting and startle parameters than companion dogs. Our results showed that independently of the sound stimulus, companion dogs had higher cortisol levels than laboratory dogs. Furthermore, the sound stimulus induced a marked autonomic imbalance towards sympathetic predominance in both laboratory and companion dogs. However a significant increase in the cortisol was observed only in companion dogs. On the other hand, in general the behavioural response was more pronounced in laboratory dogs than in companion dogs.
authors.affiliation: Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil. Electronic address: carlacfranzini@gmail.com.
authors.forename: Carla Caroline
authors.initials: CC
authors.lastname: Franzini de Souza
authors.affiliation: Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil. Electronic address: carolmaccariello@uol.com.br.
authors.forename: Carolina Elisabetta Martins
authors.initials: CE
authors.lastname: Maccariello
authors.affiliation: Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil. Electronic address: danielpenteado@gmail.com.
authors.forename: Daniel Penteado Martins
authors.initials: DP
authors.lastname: Dias
authors.affiliation: Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil; Graduate Program in Physiological Sciences, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil. Electronic address: normaalmeida@gmail.com.
authors.forename: Norma Aparecida Dos Santos
authors.initials: NA
authors.lastname: Almeida
authors.affiliation: Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil; Graduate Program in Veterinary Medicine and Graduate Program in Physiological Sciences, Federal Rural University of Rio de Janeiro, BR 465, KM 7, 23890-000 Seropédica, RJ, Brazil. Electronic address: magda.medeiros@gmail.com.
authors.forename: Magda Alves de
authors.initials: MA
authors.lastname: Medeiros
mesh_terms: D000161:Acoustic Stimulation / Q000009:adverse effects; D000704:Analysis of Variance; D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology*; D004285:Dogs; D004703:Endocrine System / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D057805:Pets; D012919:Social Behavior; D013315:Stress, Psychological / Q000209:etiology / Q000503:physiopathology
chemical_list: D006854:Hydrocortisone