The Biobehavioral Effects of Stress Related to Fear and Anxiety in Domestic Canines

Open Access
Author:
Dreschel, Nancy Ann
Graduate Program:
Biobehavioral Health
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
April 10, 2007
Committee Members:
  • Douglas A Granger, Committee Chair
  • Elizabeth Susman, Committee Member
  • David R Johnson, Committee Member
  • Laura Klein, Committee Member
Keywords:
  • lifespan
  • salivary cortisol
  • stress
  • animal behavior
  • measurement
  • canine
Abstract:
Fear and anxiety in dogs are common causes of a variety of behavioral disorders that affect the lives of dogs themselves, as well as those who live and work with them. This dissertation explores the biobehavioral stress response of fear and anxiety in the domestic dog. While it is known that these problems have profound effects on dogs’ interactions with their human companions, the effect on their physical well-being is less well studied. In all species, a physiological stress response occurs following exposure to a fear or anxiety -provoking stimulus. This stress response is thought to have both short and long-term effects on health and lifespan of the individual. Salivary cortisol as a measure of the stress response has been used in humans and other species, but factors related to collection methods, ability to collect saliva in diverse environments and under different situations, and the use of other salivary measures has not been well described for the canine species. A series of studies show that saliva can be easily collected in the home, kennel, and veterinary environments by pet owners, veterinary assistants, veterinarians, and behavior researchers. The materials and techniques used in the collection of saliva do influence the amount of saliva that can be retrieved as well as the final cortisol measurement. Cotton rope and hydrocellulose sorbettes can both be used with limited effect on cortisol concentration, and citric acid in small amounts is unlikely to have an effect on cortisol measurement, while increasing the volume of saliva collected. However, the use of beef-flavoring to enhance saliva collection in dogs is shown to introduce unpredictable error in salivary cortisol measurement. The physiological and behavioral effects of fear in dogs are described in a study of dogs and their owners’ reactions to a thunderstorm recording. It is shown that dogs have significant and long-lasting adrenal stimulation, as measured by salivary cortisol, following exposure to a known stimulus. These effects are compared to their behavioral response as well as to the behavioral and physiological response of their owners. Interestingly, owners’ responses to their dogs’ stress are not related to the amount of change seen in their dogs’ biobehavioral responses. An epidemiological survey of previous dog owners examines the long-term health and lifespan consequences of being a fearful or anxious dog. It is shown that certain fears and anxieties are prevalent in the domestic canine population and that there are prominent breed predispositions to particular behaviors that may have genetic components. These tendencies towards fear and anxiety are associated with specific health and lifespan consequences, including an increased severity and frequency of skin disorders in dogs with non-social fear and separation anxiety and a shortened lifespan in those dogs that are more fearful of strangers. Suggestions for further research into the measurement and role of fear, anxiety and other behavioral disorders in dogs are offered. This research has implications for both pet animals and working dogs, and offers a model for human fear and anxiety.