Restless nights: Shelter housed dogs need days to adapt to new surroundings

Janneke van der Laan and fellow researchers from Utrecht University's Faculty of Veterinary Medicine compared the nocturnal activity of 29 shelter dogs and 29 pet dogs in their own homes -- similar in breed, age and sex -- with the help of night cameras and a small activity tracker on their collar.

They found that shelter dogs rest much less at night than pet dogs, especially during the first two nights in the shelter. This restlessness did decrease over time, but even after twelve days in the shelter, the dogs still rested less at night than the pet dogs.

"We also saw this restlessness in hormone measurements in the urine of shelter dogs" says Janneke van der Laan. Shelter dogs had higher values of the stress hormone cortisol in their urine than pet dogs, especially during the first two days but also after twelve days. It was also striking that smaller shelter dogs, for instance Shi Tzu's and Chihuahua's, were more restless during the first two nights than larger shelter dogs, and they also had higher cortisol values.

The researchers found big differences between individual dogs: some were already quite calm during the first night in the shelter, while others barely slept for a few nights. "It seems that dogs need at least two days, but often longer to get used to their new environment, in this case the shelter," Van der Laan explains. "Humans usually also sleep less good during the first night in a new environment, for example at the beginning of a vacation."

"With our follow-up research we will zoom in even further on the welfare of dogs in shelters. But our current findings already show that it is important to pay close attention to dogs that are unable to rest properly after several nights. The shelter staff may already be able to help these dogs by for example moving them to a less busy spot in the shelter."