Human companionship and fear of thunder in dogs

WIKIMEDIA COMMONS Research investigates whether human companionship reduces stress in dogsWIKIMEDIA COMMONS

Stormy days are upsetting for dogs. Their acute hearing makes thunder stressful, and they try to hide. A dog with an exaggerated fear of noises – a phobia – might even do a little damage at home or bite whoever happens to be nearby. Magda Medeiros, doctor of veterinary medicine and professor at the Federal Rural University of Rio de Janeiro (UFRRJ), wanted to investigate how this stress and fear could be attenuated in dogs, so she decided to see if there was any difference in how two groups of dogs not exhibiting any noise phobia reacted to thunder: research animals, who are accustomed to the laboratory environment, and companion animals, who are raised at home. According to Medeiros, the conventional wisdom is that laboratory dogs tend to be more stressed out and fearful. Working under her leadership, veterinarians Carla Franzini de Souza and Carolina Maccariello submitted eight beagles from the university kennel and six companion dogs of other breeds to the following experiment: one by one, the dogs were exposed to the sound of thunder for 2.5 minutes, while researchers monitored their behavior and physiological reactions, including heart rate and level of cortisol, a hormone linked to stress. The results differed little. Dogs in both groups experienced accelerated heart rates, although the cortisol level rose proportionately more in the pets, whose level also started out higher. Stress behaviors like trembling, salivation, hiding, and others were more pronounced in the beagles (Physiology and Behavior, February 1, 2017). “Although they display significant physiological reactions, it may be that the companion animals learn to reduce their fear behavior,” says Medeiros.