Stress in dogs:
We often recognize stress related behaviour in members of our own species but do we recognize stress related behavior in dogs? Once we learn to recognize indicators of stress in dogs, we can help a stressed dog.
Dogs can feel stressed by a variety of things. Stressors can include threatening or aggressive behavior (perceived or real) from other dogs or from people, use of punishing equipment, play periods that are too long and overwhelming, or too much or too little activity day after day.
Research reveals three categories of abnormal behaviours in dogs that can be caused by stress: (1) displacement activities such as licking, grooming and pica (“pica” refers to the eating of substances that have no nutritional value) ), (2) stereotypical activities like excessive licking, flank sucking, circling or whirling, tail chasing, fence-line running, excessive barking, polydipsia (an abnormal increase in thirst) and polyphagia (an abnormal increase in appetite) and (3) behaviours like staring and ‘fly chasing’ referred to as “hallucinatory” behaviors (Casey, et al. 2002).
A stressed dog may have changes in appearance. A recent study indicated that premature greying in dogs under four years of age may be an indicator of anxiety, fear or impulsivity (“impulsivity” was defined as the loss of focus, an inability to calm his or herself, jumping on people, and hyperactivity after exercise). Analysis showed that muzzle greyness was significantly predicted by fears of loud noises, of unfamiliar animals, and of unfamiliar people. (King, et al. 2016).
Physiological indicators of stress can be identified through the measuring of the of heart rate, blood pressure, respiratory rate, body temperature and through evaluations of immune status and disease incidence. Measuring hormone secretion is also used in assessing stress (Bodnariu 2008).
The urinary, gastrointestinal, reproductive, and immune systems have been shown to be susceptible to developing disease as a result of stress (Mills , Karagiannis and Zulch 2014).
For dogs who are experiencing chronic stress from kennelling, research has shown that even one night away from the kennel situation results in a reduction in cortisol in dogs. Cortisol is a diurnal hormone that is a measure of stress. In a study done at Best Friends Animal Sanctuary in Utah, researchers measured cortisol levels in the dogs who lived there and who were participating in the “sleepover program” where visitors can take a dog for the night to their hotel. They found the cortisol levels in the dog dropped significantly when the dog participated in the sleepover program (Seckel 2017) . In another study, half of the dogs adopted from shelters displayed symptoms of various illnesses such as diarrhoea, vomiting, coughing, sneezing and skin problems. It was suggested that these conditions may be due to the immunosuppression caused by the previous stress of kennelling (Bodnariu 2008).
Being left on their own is stressful for many dogs as they are social animals. Studies have shown that at 5 weeks of age, dogs experience an elevation in cortisol after separation (Nagasawa, et al. 2014). Dogs who have separation-related problems may show it through destruction of property, excessive vocalization and house-soiling. A study on treatment for separation-related behavior revealed that dogs treated with systematic desensitization had significant reductions in the frequency and intensity of the separation-related behaviors and that, three months after the treatment ended, most of the dogs showed almost complete elimination of the problem behaviour (Butler, Sargisson and Elliffe 2011).
Certain training methods can elicit stress signals in dogs. The results of a study comparing the behavior observed in dogs participating in training classes at two training schools that used two different types of training methods results suggested that training methods based on positive reinforcement are less stressful for dogs. One school used positive reinforcement (where a food reward was given) in training while the other school used negative reinforcement (where an aversive disappeared when the dog complied). The dogs who attended the classes at the school using negative reinforcement displayed lowered body postures and displayed other signals of stress while the dogs who were trained with the positive reinforcement showed increased attentiveness toward their owners. (Deldalle and Gaunet 2014).
Recognizing the indicators of stress in dogs helps us make changes to reduce stress and anxiety in dogs.