Pet shelters often require that the new owner pay adoption fees, have adequate space for the new pet and already have a veterinarian. The shelter also asks potential pet owners other questions during the process to ensure a good match.
Most states also require the pet to be spayed or neutered and up-to-date on all vaccinations before leaving the shelter. Shelters also have the potential owners fill out an application. The application may ask about the type of housing they have, the number and ages of their children, any other pets and about any previous pet ownership experience. They may also ask about activity level and work schedules to make sure the personality of the pet is appropriate for the owner. For example, a particularly needy dog would not likely be released to a single owner who works 60 hours a week, or a scratch-happy cat won't be permitted to co-habituate with a newborn.
Shelters work to find the best new parent for the pets so the animals do not end up back at the shelter. Shelters also sometimes contact references. Every shelter and state has its own requirements, so it is best for those interested in adoption to contact the local shelter directly about its rules.