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Shelter dogs have high levels of stress

In a new study from Utrecht University, scientists have investigated the mental well-being of shelter dogs by examining stress hormones. 

“Dogs can suffer from chronic stress in environments that are sub-optimal to their needs, such as in many kennel environments,” wrote the study authors. 

“Chronic stress may exceed the animals’ adaptive capacity and thus, threaten its welfare state. Chronic stress may even elicit medical and behavioral problems in the long term. Therefore, to improve canine welfare, reliable and feasible non-invasive indicators of long-term stress levels need to be evaluated.”

It comes as no surprise that shelter dogs are stressed. They are exposed to lots of other dogs, strange humans and are more isolated from the outside world.

“We know that a shelter is not a stress-free environment for dogs, even though staff members do their best to achieve the highest possible welfare,” said lead researcher Janneke Van der Laan. “Even if you organize a shelter in the best possible way, there are still stress factors, such as crowds of other dogs and not being able to go outside as often as usual. And most important: the dog is gone from their old, familiar environment.”

The scientists carried out the research by measuring levels of cortisol, a stress hormone that is found in humans as well as dogs. The cortisol levels can be measured from hair samples, so the research team collected hair from dogs at the beginning of their stay at a shelter, throughout the course of their stay, and after they were adopted out.  

“In addition to the cortisol measurements in hair, we also measured cortisol values in the dogs’ urine. This gives a short-term picture while the hair measurements show the long term,” explained van der Laan.

“We took daily measurements in the shelter for over a year. After adoption, the new owners – after clear instructions – cut the dogs hair and sent it to us. They were helpful and enthusiastic, and were very interested in what their dog had experienced before adoption.”

The dogs’ cortisol levels started at the same levels of other domestic dogs but rose during their time at the shelter, peaking after six weeks. Fortunately, these stress levels fell at about the same rate when dogs found new homes and ultimately returned to normal. One surprising (and so far unexplained) result was that smaller dogs exhibited higher cortisol levels than their larger counterparts. 

The study shows that even a shelter like the one used, which does its best to improve welfare for animals, is a stressful place for dogs. The research highlights the need to get dogs adopted as soon as possible to good homes. 

The study is published in the journal Scientific Reports.  

By Zach Fitzner, Staff Writer

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