It is something we all know, but despite the care shelters may provide, they are a stressful environment for dogs. Prolonged and excessive cortisol levels can impair the immune system and lead to serious health issues in humans and animals. Research at the Utrecht University in the Netherlands compiled these results in April 2022 by measuring the amount of the hormone cortisol in dogs before, during and after their stay in a shelter.

Researchers took daily measurements for over one year. There was no difference between the cortisol levels of dogs when they entered the shelter and the control groups of dogs living in a family home. After six weeks in the shelter, cortisol levels rose by one third (on average, from 16pg/mg to 21.8pg/mg. Dog pounds are much more stressful than shelters.

Measurements were then taken at six weeks and six months after adoption. Most new owners, adopters, were willing to carefully cut samples of fur and send them to the laboratory. Cortisol levels dropped, slowly moving in the direction of the values at admission to the shelter. Cortisol accumulates in hair, in humans and animals; this technique has been used extensively. By measuring levels in the hair, researchers can get an idea of the stress response and recovery over weeks and months – depending on the length of the hair or fur examined. Cortisol can also be measured in urine, which gives a short-term picture, while hair measurements show long term levels.

A surprising result is that smaller dogs generally have higher cortisol levels than larger dogs. There is no clear hypothesis about why that is, but fortunately, smaller dogs and puppies tend to be the most popular adoptees. All the examined dogs were in the same shelter, and there are significant differences between shelters, nationally and internationally. The shelter in this study has a pioneering role in improving the welfare of dogs. They replaced bars with a special glass that reduced noise, played relaxing music, set up a room like a lounge room where staff and volunteers went for breaks or computer work and allowed dogs time to relax there. Just spending time with a dog reduces stress.

The number of dogs being surrendered post-Covid lockdowns has dramatically increased. Many people are back at work and returning to social life. They have no time for a dog. Before and during the lockdown, shelters were empty or almost empty. Financial difficulties are also a common reason for surrenders; pet food, medications and veterinary fees are expensive, and they cannot always be the top priority in a person’s or family’s budget.

Pam Brandis, 
 Dip. Canine Prac.