A dog that has just left a shelter has lost everything it knew, and the first days in a new home are hard for it. Most of what helps in the first weeks is doing less, not more.
Check that the microchip is registered to you, with your current phone number. A chip only helps if the details behind it are right.
What to do in the first hour if a dog gets out is on the missing pet page.
How to introduce a new dog to the pets already in the house is on the page on introducing a new pet. Keep the vaccine dates, the weight and the first vet notes in My Pet, so the record starts on day one.
A dog that was house trained before can still have accidents in a new home. In a study of dogs one week after adoption, it was the problem owners reported most.
A popular rule of three says a new dog needs three days to decompress, three weeks to learn the routine and three months to feel at home. The ASPCA's professional site uses it, and Humane World for Animals mentions it.
The rule comes from rescue work, not from research. The only account we found of where it started is on the site that says it created it, and we could not check that account.
We found no study that tests it. The research that does exist says a dog keeps changing well past three months. A 2023 study followed 99 adopted dogs from five shelters in Ohio for up to six months.
So some of a dog's real personality shows up only after it has settled, and that is normal.
The numbers depend on the shelter and on how long each study waited.
| Study | How long after adoption | Returned or no longer in the home |
|---|---|---|
| Five shelters in Ohio, 2023 | 6 months | 7.1% of dogs |
| Charleston Animal Society, 2015 to 2019 | 6 months | 16.3% of dogs |
| Six US shelters, American Humane, 2013 | about 6 months | about 12% of dogs, with 87.6% still at home |
| One shelter, ASPCA researchers, 2014 | 30 days | about 4% of the dogs and cats whose owners answered the survey, with 96% still at home |
The two studies that looked at timing disagree. The American Humane study found that most of the dogs and cats that left their homes did so in the first two months. A 2020 study of returns found that more than half of the returned dogs had been in their homes for more than 60 days.
The American Humane study also found that dogs taken to a vet were far more likely to stay in their new homes. That is a link, not proof that the vet visit caused it.
Behavior was the top reason for returns, and behavior can often be helped. Start with a vet visit, because pain changes how a dog behaves. The scared dog page has what helps a frightened dog, and the dog body language page shows how to read one.
Still choosing where to adopt? Read this first: How do I check a shelter or rescue before I adopt?
Shelter and rescue websites use words that do not mean the same thing everywhere. These explanations follow the Shelter Terminology document of the Association of Shelter Veterinarians, updated in February 2017.
| Word | What it means |
|---|---|
| Managed admission | An owner who wants to give up an animal is given an appointment, so that animals arrive only as fast as the shelter has space and resources for them. |
| Live release rate | The share of animals that leave the shelter alive, whether adopted, reclaimed by an owner or transferred to another group. It can be worked out in three ways, so ask which one the shelter uses. |
| No kill | There is no single definition. Shelters that use the words reject euthanasia as the main way to manage numbers, but their rules differ, and many have aimed for a live release rate of 90%. |
| Trap-neuter-return | A way to manage outdoor cats without taking them into a shelter. The cats are humanely trapped, sterilized, vaccinated and marked by removing the tip of one ear. The R can stand for return, release or relocate. |
| Foster-based | The animals live in the homes of volunteers instead of a shelter building. Rescue groups are often run this way. |
| Return policy | What the group will do if the adoption does not work out. The association opposes blanket policies that forbid returns, discourage them or bar the person from adopting again. |
The association's Guidelines for Standards of Care in Animal Shelters add that a live release rate cannot be used alone as a measure of success. Ask the shelter what its own words mean.
Sources read 23 September 2026. Quotes are copied word for word from each source.