Even a brief, one‑week stay with a foster family can significantly boost the welfare of dogs waiting in shelters, a new study has found.
Researchers from Virginia Tech’s School of Animal Sciences, working with Arizona State University and two shelters in Arizona and Virginia, tracked 84 dogs over 17 days: five days in the shelter, seven in a foster home, and five days back in the shelter. Researchers gathered over 1,300 urine samples to assess levels of the stress‑related hormone cortisol and fitted dogs with collar devices that recorded how much they rested and moved around.
During the week in foster homes, dogs’ cortisol levels dropped significantly, with effects twice as large as those seen in earlier studies of shorter outings. The dogs also spent more time resting, indicating that time in a home environment allowed them to truly decompress. Importantly, when the dogs returned to the shelter, their cortisol levels were not higher than before the foster stay, suggesting that the break provided relief without making the transition back more stressful.
Familiar “Best Friends” Help in Kennels
The study also looked at how dogs were affected by being housed with a familiar canine companion after returning from foster. Before fostering, dogs kenneled with a compatible buddy did not show major differences in stress or activity, compared to dogs housed alone or with different dogs.
But after the week away, dogs reunited with a known kennelmate rested more and showed less high-intensity activity than dogs housed alone or with a new companion. Researchers say familiar relationships can act like a “best friend” in a stressful setting, helping dogs settle and cope more easily.
Foster Programs Boost Adoptions
This new research builds on earlier findings that even very short breaks from the shelter can help dogs find homes. In a previous study involving 51 shelters and nearly 28,000 dogs, brief outings of one to four hours increased dogs’ chances of adoption fivefold, and one or two nights in foster care made dogs more than 14 times as likely to be adopted.
Most of those adoptions did not come directly from foster families, but from the increased visibility dogs gained while out in the community or featured on social media. Getting dogs into real homes, even temporarily, helps potential adopters see them as individuals and can fast-track them to permanent families.
What Shelters Can Do Now
Researchers say foster breaks and pairing familiar kennelmates are practical, low-cost strategies that shelters can implement right away to improve dogs’ well-being. Simply giving dogs time to rest in a home and keeping them with known companions when they return can reduce stress and support better outcomes.
“We keep finding that when dogs leave the kennel and go into a home, they do better,” says lead author Lisa Gunter, an animal behavior and welfare expert at Virginia Tech. The study, published in the journal PeerJ, underscores how vital foster programs and thoughtful housing arrangements are for helping shelter dogs feel — and fare — better.
