Effects of Olfactory and Auditory Enrichment on Heart Rate Variability in Shelter Dogs
Centre for Animal Welfare and Ethics, School of Veterinary Sciences, University of Queensland, White House Building (8134), Gatton Campus, Gatton, QLD 4343, Australia
Royal Society for the Prevention of Cruelty to Animals, Queensland, Wacol, QLD 4076, Australia
Author to whom correspondence should be addressed.
Received: 20 July 2020 / Revised: 4 August 2020 / Accepted: 6 August 2020 / Published: 10 August 2020
Many pet dogs end up in shelters, and the unpredictable and overstimulating environment can lead to high arousal and stress levels. This may manifest in behavioural problems, and decreased welfare and adoption chances. Heart rate variability is a non-invasive method to measure autonomic nervous system activity, which plays an important role in the stress response. The sympathetic nervous system is responsible for increasing the dog’s arousal in response to stress and the parasympathetic nervous system is responsible for counteracting the arousal and calming the dog. Environmental enrichment can help dogs to be more relaxed, which is likely to be reflected by increased parasympathetic activity. Dogs’ heart rate variability responses to three enrichment methods capable of reducing stress—music, lavender and a calming pheromone produced by dogs, dog appeasing pheromone and a control condition (no stimuli applied) were compared. Exposure to music appeared to activate both branches of the autonomic nervous system, as dogs in that group had higher heart rate variability parameters reflecting both parasympathetic and sympathetic activity compared to the lavender and control groups. We conclude that music may be a useful type of enrichment to relieve both the stress and boredom in shelter environments.