Dogs experience more stress and restless nights for up to 12 days after being sent to a shelter, researchers have found.
They also discovered that smaller breeds such as Shih Tzus and Chihuahuas suffer more than larger ones, especially during the first two nights in a new environment.
The Utrecht University study compared the nocturnal activity of dogs placed in a shelter to pets in their own homes.
The study comes amid fears from experts that there will be an increase in the number of dogs ending up in shelters when people go back to the office after working from home during the coronavirus crisis.
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Restless: Dogs experience more stress and sleepless nights for up to 12 days after being sent to a shelter, researchers have found
Researchers found that shelter dogs rested much less at night than pets, especially during the first two nights in the shelter.
This restlessness did decrease over time, but even after 12 days in the shelter, the dogs still rested less at night than pet pooches.
'We also saw this restlessness in hormone measurements in the urine of shelter dogs,' said Janneke van der Laan, the study's lead author.
'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 12 days.
'It was also striking that smaller shelter dogs, for instance Shih Tzus and Chihuahuas, were more restless during the first two nights than larger shelter dogs, and they also had higher cortisol values.'
The study involved 29 shelter dogs and 29 pet dogs all similar in breed, age and sex.
Content: The Utrecht University study compared the nocturnal activity of dogs placed in a shelter to pets in their own homes (file photo)
Night cameras and a small activity tracker on the animals' collars were used to monitor their sleeping habits.
The researchers found big differences between individual dogs: some were already quite calm during the first night in the shelter, while others barely
