What happens when animal shelters become full?

It depends on the animal shelter, how they handle it when they get full. Some shelters euthanize or put to sleep more animals, even the adoptable animals. Other animal shelters only euthanize the unadoptable, untreatable animals, and they try to find additional foster homes for their current animals, and if necessary, stop admitting additional animals temporarily. If you ever turn over an animal to an animal shelter, be sure to ask what that shelter's policy is if they get too full or can not find a home for or locate the owner of an animal within a certain time. You may want to consider only turning in an animal to an animal shelter who won't euthanize them too hastily or unnecesssarily.