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Do Dogs Suffer Stress in Animal-Assisted Therapy Sessions?

Physiological indexes of stress were taken before and after therapy sessions.

Key points

  • It is possible that dogs may show stress during therapy sessions because patients are strangers and may touch the dogs in unwelcome ways..
  • The hormone cortisol is released when a dog is under stress and its concentration may be measured by taking samples of saliva.
  • Cortisol concentrations indicate no apparent rise in stress in therapy dogs as a function of participating in animal-assisted therapy.
Courtesy of Vancouver EcoVillage
Source: Courtesy of Vancouver EcoVillage

The Covid-19 pandemic, with its restrictions on social gathering and social distancing, has had a massive negative impact on many therapy dog programs. My own dogs have worked as therapy dogs with the Vancouver EcoVillage group for a number of years. However, with the onset of the virus and the imposition of regulations on gatherings, the program was forced to completely shut down for nearly two years since it was oriented toward group de-stressing sessions which typically involve the elderly, large groups of university students, or gatherings of people in work or educational settings. I was therefore pleased when health authorities eased the restrictions a bit and the therapy dog program could start to ramp up again.

A Potential Problem for Therapy Dogs?

I mentioned this to a friend who had been considering enrolling her miniature schnauzer as a therapy dog. She told me, "The more that I have been thinking about this, the more uncomfortable I've grown about the situation. It doesn't have to do with the virus, but rather the stress that the dogs must feel during the therapy session. Think about it: They are approached by complete strangers who encroach upon their personal space and then reach and touch them. If the people are elderly, or have movement limitations, their touching might be rough and uncomfortable. The same thing goes for kids who often grab rather than pat the dogs. I understand that the effects that the dogs have on people are positive and result in a reduction of stress, but I am afraid that the human stress reduction may come at the cost of an increased stress level in the dogs involved in the therapy sessions. Has anybody done any research on this?"

I assured her that I would do a quick literature search and get back to her.

The Stress Response

It turns out that in the past couple of years not much research has been done on this topic. However, I did find one brief report—actually a pilot study—conducted by a team of investigators led by Flavia Dye of the University of Agricultural Sciences and Veterinary Medicine (USAMV) in Romania. It is a relatively small study, involving only seven therapy dogs (differing in age, sex, breed, and work experience). However, the measures which were taken were state-of-the-art, and there were multiple tests administered to each dog.

The measure of stress which these researchers used was cortisol concentration in the dogs. You can think of cortisol as nature's built-in alarm system. When you encounter a perceived threat, your hypothalamus (a tiny region at your brain's base) sets off this alarm response in your body. Using a combination of neural and hormonal signals, it causes your adrenal glands (located on top of your kidneys) to release a surge of hormones—the main ones being adrenaline and cortisol.

Adrenaline increases your heart rate and also elevates your blood pressure and increases the release of energy supplies. Cortisol, usually referred to as the primary stress hormone, increases the concentration of glucose in the bloodstream, enhances your brain's use of this glucose supply, and increases the availability of substances that can repair tissues. In other words, the combination of these hormones makes it easier for you to fight for your life if needed, or to quickly run away from danger.

Cortisol is a very useful measure of the stress that an animal or person is experiencing, since it can not only be measured in blood samples, but also in simple swabs of saliva.

The New Data

For this new study, measures of the salivary cortisol concentrations were taken during working days (when the dogs engaged in a therapy session) versus resting days. These saliva samples were collected before and after animal-assisted therapy sessions for two days. As a control baseline, samples were taken at identical times on two resting days.

If the dogs were suffering from stress provoked by the therapy sessions, it was expected that the cortisol levels in their saliva would have increased. However, there were no significant increases in salivary cortisol values measured before and after the sessions, and no significant difference in the overall cortisol levels between resting days and working therapy days.

Although the sample size is small, the investigators still felt that they could assert that this study indicated that dogs were coping well with animal-assisted therapy sessions and were not responding in a stressful manner to the interactions associated with being a therapy dog.

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Flavia Dye, Camille Chabaud, Veronica Sergi, Eva Teruel, Ionel Papuc, Cécile Bienboire-Frosini (2021). Do dogs cope with animal-assisted therapy sessions, and how? A pilot study. Research Gate,…

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