Animal Shelters: Less Stress and More Rest for Dogs Temporarily Housed Outside the Kennel

Temporary foster care reduces stress levels and increases rest time for dogs living in shelters. A study from the University of Arizona evaluated the impact of one- to two-night foster programs on urinary cortisol levels, resting heart rate, and the proportion and quality of sleep in kenneled dogs. Five animal shelters in the United States participated in the study. Temporarily leaving the confined, interaction-poor environment of the shelter has a significant impact on the well-being and behavior of dogs awaiting adoption.

Social isolation is one of the main stressors for dogs living in animal shelters. In addition to the lack of freedom of movement due to the size of the cages, life in a shelter also limits dogs’ ability to interact with other dogs and with humans. In this setting, dogs are subjected to several stressors, including high noise levels, a lack of space and activity, sleep deprivation, and a loss of social bonds. According to previous research, noise levels in kennels can reach or even exceed 100 dB. This disruptive environment, combined with isolation, causes dogs to gradually lose control over their daily lives. Their behavior becomes apathetic; they show less interest in visitors over time and eventually withdraw to the back of their cages.

Each year, between 4 and 5.5 million dogs are taken to shelters in the United States. While many will be adopted or reunited with their owners, about 14% of these dogs will be euthanized. To increase the number of adoptions, the University of Arizona studied the effects of kennel life and the benefits of a short-term placement outside the shelter—for just a few nights—on the dogs’ behavior and stress levels. The goal was to measure the impact of short-term foster care on the sleeping patterns of shelter dogs. In addition to measuring cortisol levels—one of the physiological markers of stress—connected collars were used to monitor the dogs’ temperature, heart and respiratory rates, activity levels, and body positions.

The team monitored the stress levels of dogs at five shelters of varying capacity (ranging from 600 dogs per year to more than 6,000) by measuring cortisol levels before, during, and after each evening spent outside their kennels. A total of 207 dogs participated in the study, and 1,076 cortisol readings were collected and analyzed. At all shelters, the research team found that the ratio of cortisol to urinary creatinine had decreased significantly during the dogs’ stay with foster families, but had returned to its initial level after they returned to the shelter. However, the extent of the reduction observed varied from one shelter to another. All the dogs experienced their longest periods of uninterrupted rest during their stay with host families—a sort of respite from the stressful life at the shelter. Shelter dogs sleep just under 11 hours a day, compared to 14 hours for other dogs. These placements also provided insights into the dogs’ individual behaviors within a home—information that will help better inform potential adopters.

Ultimately, these nights spent with families—which should be viewed as a beneficial but short-lived form of enrichment—are only a first step. To reduce stress and improve the lives of shelter dogs in the longer term, we still need to study the benefits of more frequent educational outings and long-term foster placements, and take into account the environmental factors specific to each shelter.