(These are general definitions. Each shelter might use slightly different definitions)
- Live release rate: Number of animals taken in in versus number of animals leaving alive
- No Kill Shelters:
- No Kill shelters are generally expected to have a live release rate of 90% or more. They do not euthanize animals based on time limits or to make space for new animals, but this 10% leaves room for animals that may need to be euthanized for medical or behavioral reasons. Animals that are treatable or rehabilitatable will not be euthanized, but it is important to note that individual shelters can define these terms however they want. One shelter may consider a cat with feline leukemia or a dog with a bite history to be treatable or rehabilitatable, but another shelter may not. No Kill shelters are often closed shelters, but this is not always the case.
- Traditional Shelters:
- Traditional shelters are shelters that euthanize animals based on time limits, space requirements, or perceived adoptability. It is important to note that individual shelters can define terms like adoptablity however they want. One shelter may consider a kitten needing to be bottlefed or a black dog (black animals are statistically adopted less often) adoptable and be willing to put in the effort to get them ready for their forever homes, while another shelter may choose to euthanize them. Traditional shelters are usually open shelters.
- Closed shelters:
- Closed shelters are shelters that do not automatically accept any new animal that comes to them. They may allow intakes by appointment or waiting list only. They may also be a hybrid of open and closed, such as having a specific jurisdiction or niche that they cover. For example, a shelter may immediately accept all intakes from within a certain zip code or breed, but put other intakes on a waiting list.
- Open shelters:
- Open shelters automatically accept all intakes.
- Trap-Neuter-Release (TNR):
- TNR programs aim to reduce overpopulation of stray animals, especially cats. Stray and feral cats are captured and spayed or neutered, as well as tested for diseases. Friendly strays can be put up for adoption. Healthy feral cats are ideally returned to their familiar territory, if it is safe for them. Otherwise, they are introduced to feral cat colonies, often serving as mousers on farms. Feral cats with contagious conditions like FIV or FeLV may be euthanized or potentially made available for adoption, depending on the organization.