What helps animals get adopted faster: what published studies found

Most shelter data can't show whether an animal's photos, listing or promotion changed how long it stayed. Published studies have measured some of these factors. This page summarizes what they found.

From published studies, not our data. Every figure below is quoted as reported by the study's authors. The public shelter open data behind Shelter Insights has no per-animal marketing fields, so we can't measure these effects in it.

What the studies found

Photo quality

Overall photo quality had the largest impact on time to adoption. Young dogs with poor photos averaged 43 days versus 14 days with great photos; adult dogs showed a similar trend that was not statistically significant. Eye contact with the camera, standing, an outdoor setting, a correctly sized photo and a sharp image were linked to faster adoption. A cage in the photo, a bandana or a visible tongue had no effect.

Study: Lampe & Witte (2015), Journal of Applied Animal Welfare Science. Where: United States. Sample: 468 adopted black Labrador-mix dogs listed online. Read the source

Photo traits

Dogs photographed in a kennel had an average stay of 11.54 days and dogs with mouths closed 14.44 days. Dogs with erect ears had 18.32 days and dogs photographed in a natural setting 19.57 days. The authors note most effect sizes were below 0.2 (small).

Study: "Picture Perfect Pups" (2020), Animals. Where: Australia (PetRescue). Sample: Staffordshire bull terriers (n = 3,988), Labrador retrievers (n = 2,246), Jack Russell terriers (n = 2,088). Read the source

Words in the listing

Average stay was 35.4 days (median 18 days). Stays were shorter when the description included "make you proud", "independent", "lively", "eager" or "clever", and longer when it included "only dog", "dominant", "sensitive" or "happy-go-lucky". Some effects differed by breed.

Study: "Descriptive Texts in Dog Profiles Associated with Length of Stay Via an Online Rescue Network" (2019), Animals. Where: Australia (PetRescue). Sample: 70,733 dogs. Read the source

Writing style

Ads for pets that were adopted were more likely to use a concrete, analytic style (facts such as breed, age, weight, health). More storytelling-style language was associated with longer waits.

Study: University of Oregon study of Petfinder ads (2019). Where: United States (Petfinder). Sample: Nearly 680,000 adopted and unadopted pet ads. Read the source

Brief outings and 1 to 2 night fosters

Brief outings increased dogs' likelihood of adoption by 5.0 times and 1 to 2 night fostering stays by 14.3 times. Programs did better when community members, rather than only staff and volunteers, took part.

Study: Gunter et al. (2023), Animals, with Maddie's Fund. Where: United States, 51 shelters. Sample: 1,955 dogs that went on an outing or short foster stay; 25,946 comparison dogs. Read the source

Fee-waived adoption events

Six to 12 months after a fee-waived event, 93% of dogs and 95% of cats were still in the home. This study measured whether adoptions lasted, not how fast animals were adopted.

Study: Maddie's Matchmaker Adoptathon follow-up (2011 event), University of Florida. Where: United States. Sample: 1,928 adopters surveyed; 1,099 responded. Read the source

Photo setup (survey experiment)

Participants rated a dog photographed in a cage as least attractive and the same dog inside on a neutral background as most attractive. People in the photo, head tilt and mouth position made no significant difference. These were ratings, not real adoptions.

Study: Faunalytics-published study of shelter dog photos. Where: United States. Sample: Three online experiments with 120, 215 and 172 participants. Read the source

Coat colour: black cats

Coat colour overall was negligibly associated with outcomes, but black cats had the highest euthanasia and lowest adoption rates and white cats the lowest euthanasia and highest adoption rates; the pattern stayed weak but significant after controls. In 1,219 entirely black cats, October adoption and transfer percentages were comparable to or lower than other months, so outcomes did not improve around Halloween.

Study: Carini, Sinski & Weber (2020), Animals (open access). Where: Louisville, Kentucky, USA (public shelter, 2010–2011). Sample: 7,983 cats. Read the source

Coat colour: dogs (mixed evidence)

In the Czech study, abandoned black dogs had the longest median stay before adoption (32 days) and brindle and multicolor dogs the shortest (17 and 18 days). The U.S. study found no relationship at the bivariate level; after controls, entirely black dogs had somewhat lower odds of adoption, but breed category, size and purebred status were stronger predictors and the authors concluded “Big Black Dog Syndrome was not supported.” Coat colour effects appear small and vary by shelter.

Study: Voslářová et al. (2018), Society & Animals (abstract); Sinski, Carini & Weber (2016), Anthrozoös (abstract). Where: Czech Republic shelter; Louisville, Kentucky, USA. Sample: Czech study: not stated in abstract; U.S. study: 7,440 dogs (2010–2011). Read the source

Kitten fostering barriers

The most common concerns about fostering kittens were the time (79%), cost (78%) and space (77%) required. One-third of the sample was open to fostering with a shelter, and most interested people had not seen fostering program advertising. The authors suggest realistic expectations and support such as transportation and in-home veterinary visits.

Study: McDonald et al. (2022), Frontiers in Veterinary Science (open access). Where: Los Angeles County, California, USA. Sample: 283 adults in 12 high kitten-intake zip codes. Read the source

Try it: check a photo or listing text with our free photo and listing checker. It runs in your browser and nothing is uploaded.

Practical takeaways for shelter teams

Photos: a clear, sharp, well-composed photo with the animal looking at the camera was linked to faster adoption in the U.S. study. Results on setting varied: one study favored outdoor photos, another found kennel photos had shorter stays, and a survey found cages were rated least attractive. Image quality is the most consistent finding.
Listing wording: concrete facts (age, size, health, how the animal does with others) were associated with adoption in a large Petfinder analysis. Some specific words were linked to longer or shorter stays in Australian data, and the effect differed by breed.
Outings and short fosters: time out of the shelter with a person was linked to much higher odds of adoption, especially when community members took part.
Coat colour: studies disagree on how much coat colour matters; where effects were found (black cats, black dogs in one Czech shelter) they were small, and other factors such as breed and size mattered more.
Recruiting kitten fosters: being upfront about time, costs covered and space needed addresses the top concerns people reported.
Fee-waived events: follow-up research found most animals adopted during a free event were still in their homes 6 to 12 months later.

Caveats

The outing and foster study was not randomized. Dogs that took part already had longer stays before the program, and shelters chose which dogs went, so the size of the effect may partly reflect which dogs were picked.
In the 2020 photo study, the authors note most effect sizes were small (below 0.2) compared with the roughly four-week spread in stay lengths.
The photo and wording studies are observational: they show associations, not proof that changing a photo or phrase causes a faster adoption.
Several studies cover one breed type or one country, and results may not apply to every shelter or to cats.
The photo survey measured how attractive people rated a dog, not real adoptions.

Questions

Does photo quality affect how long a shelter dog waits?

In a U.S. study of 468 adopted black Labrador-mix dogs, overall photo quality had the largest impact on time to adoption: young dogs with poor photos averaged 43 days versus 14 days with great photos.

Do short foster stays help shelter dogs get adopted?

A 51-shelter U.S. study found 1 to 2 night fostering stays increased dogs' likelihood of adoption by 14.3 times and brief outings by 5.0 times, though dogs in the programs already had longer stays before taking part.

Is this based on Shelter Insights data?

No. Everything on this page comes from published studies. The public shelter open data we analyze does not record photos, listings or promotion for each animal.

For what our open data does show, see the length-of-stay benchmarks, the foster program impact guide and our guides.