Regardless of how well the dogs are cared for, a shelter may be a stressful atmosphere for them.

Researchers at Utrecht University wanted to know if the quantity of the stress hormone cortisol in dogs' hair signals how stressed they are before, during, and after their stay in the shelter.

There is no difference in cortisol levels between dogs entering the shelter and the control group of household dogs.

Cortisol levels in the hair appear to have increased by one-third after six weeks in the shelter (on average from 16 pg/mg to 21.8 pg/mg).

Cortisol levels decreased six weeks and six months following adoption, heading in the direction of the values upon admission to the shelter.

Cortisols in dogs' hair
(Photo : ALEKSEY FILIPPOV/AFP via Getty Images)

Cortisol, a stress hormone, builds in the hair of both humans and animals.

This approach has been utilized frequently in humans and other species, and 15 research investigations on dogs have been conducted so far.

In addition to measuring cortisol levels in the dogs' hair, they also assessed cortisol levels in their urine.

Thus, according to Janneke van der Laan, a researcher, this gives a short-term picture, whereas hair measurements provide such a long-term view.

Of course, there are significant differences amongst shelters not just in the Netherlands, but across the world.

Dogs are often maintained separately in the Netherlands, but they are frequently kept in groups in other nations.

"We know that a shelter is not a stress-free place for dogs," Van der Laan added, "even though staff members try their utmost to attain the maximum possible wellbeing."

"Even if you organize a shelter in the greatest way possible, there are still stress issues, such as crowds of other dogs and not being able to go outdoors as frequently as normal, and, most importantly, the dog is removed from their old, familiar habitat," as per ScienceDaily.

Read more: Low Levels of Cortisol in People with Bipolar Disorder Linked to High Depression Risk

Cortisols

Cortisol is a glucocorticoid hormone that your adrenal glands manufacture and release.

Hormones are compounds that connect with your organs, skin, muscles, and other tissues to help your body coordinate various functions.

These cues tell your body what to do and when to do it.

Steroid hormones are glucocorticoids. They regulate metabolism in your muscles, fat, liver, and bones, as well as aggravation in all of your physical tissues.

Glucocorticoids also have an impact on sleep-wake cycles, as per Cleveland Clinic.

Adrenal glands, also referred as suprarenal glands, are small, triangle-shaped glands that are located above the two kidneys.

It's also crucial to understand that, medically speaking, there are several types of stress, such as:

Chronic stress: Chronic stress arises when you are constantly presented with situations that make you upset or apprehensive.

Persistent stress can be produced by a variety of factors, including difficult or time-consuming employment or a chronic condition.

Traumatic stress: Occurs when you face a life-threatening situation that causes fear and a sense of powerlessness.

Traumatic stress can be caused by, for example, seeing an extreme weather occurrence, such as a tornado, or by witnessing war or sexual assault.

In certain situations, these occurrences might result in post-traumatic stress disorder (PTSD).

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