Animal Shelters

Animal shelters, at a minimum, provide a place for lost or abandoned animals to find homes. Many provide human law enforcement services, behavioral evaluations, remediation and enrichment, health and spay/neuter services, humane education and much more.

Animal shelters provide care and treatment to animals needing protection, attempt to find homes for homeless animals and reunite lost pets with their families.  When necessary, animal shelters provide a humane death for homeless or unadoptable animals.  Today’s shelters range from single rooms with multiple cages to state-of-the-art facilities with amenities that might rival some hotels.  The “luxury” features, like piped-in music and waterfalls serve to reduce the stress to the animals in the facilities and make the shelter an inviting and positively viewed destination rather than a depressing one to be avoided—thus increasing the chances that the animals at the shelter will find a new home. 

Animal shelters can be categorized as follows: 1) municipal animal control agencies, run by city or county governments; 2) private, non-profit agencies overseen by a board of directors; and 3) private, non-profit agencies with a government contract to provide animal control services. 

Municipal animal control agencies are typically open-access. This means that they take in any animal that is brought to their door by the public or seized by animal control agents on patrol.  Municipal agencies, because of their open-access status, will at times find it necessary to euthanize animals in their care to make room for incoming animals.  This is not something that is done lightly nor without regret by those working within these agencies—it is, however, the current state of animal control in this country.  Between three and four million cats and dogs are euthanized in shelters in the United States annually.  This number reduced dramatically over the last few decades due to the hard work people in the animal sheltering community have done to improve adoption procedures, increase the number of animals that successfully find their way back to their families and by aggressively getting the “spay/neuter” message out to the public, thus decreasing the number of animals reaching shelters today.  It is estimated that each spay or neuter results in .72 fewer dogs and .57 fewer cats entering the shelter (Zawistowski 2008).  Municipal agencies are funded by the government; but most are underfunded to do the job they are tasked to do and often have non-profit arms to help close the gap between costs and funding.

Private non-profit agencies rely on donations and grants to fund their programs.  Many private agencies are limited-access, sometimes called “no-kill” facilities, as they do not euthanize animals to make room for more.  They do, however, find it necessary to turn some animals who are brought to them away if they do not have space available at that time.  Both municipal and private agencies set up foster-care networks to increase the number of animals they can serve at a given point in time. 

Shelters, both municipal and private may provide other services for the public if they have sufficient resources to do so.  These services may include animal health services such as exams and spay/neuter surgeries, behavioral evaluations and training, humane education, and others. 

Any shelter can use the term “Humane Society” or “SPCA” in their name. These are generic terms that don’t imply that the shelter is part of a larger organization or has special powers.  In fact, most humane societies and SPCAs are independent of each other. SPCA stands for Society for the Prevention of Cruelty to Animals.   National organizations do not have any oversight or governing power over these independent agencies.  National organizations offer guidelines and recommendations for animal shelters that are often followed (Fekety 1998).

Historic Roots
Shelters for companion animals developed from the impoundments that were common in colonial towns and that were used to contain wandering livestock and strays.  The poundmaster would then take these wandering animals and confine them at the impoundment.  If the owner wanted to reclaim the animal they would need to pay the poundmaster a redemption fee.  The poundmaster did not earn a salary and, therefore, depended on redemption fees to live.  If animals were not reclaimed, the poundmaster would slaughter the livestock and sell the meat.  Unfortunately, since companion animals did not generate a profit, it was not uncommon for them to suffer an untimely death.  

The American Society for the Prevention of Cruelty for Animals (ASPCA®) was founded by Henry Bergh in 1866.   The early focus of the ASPCA was the mistreatment of horses that worked in the city transporting people and freight.  Soon after, similar organizations were created in Boston, Philadelphia and San Francisco.   

Henry Bergh fought against the inhumane treatment of animals at the “pound” in New York City.  In fact there was a cartoon depicting him as the only mourner following the poundmaster to the river to drown the impounded dogs.  He was, however, adamant that the ASPCA should not take over animal control for New York City.  He believed that the city would never provide enough funding to do the job well…a state of affairs that is common still today across the country.  In 1894, six years after the death of Henry Bergh, the ASPCA board of directors voted to take on the management of the New York City’s animal shelters a contract they held until 1995 (Zawistowski 2008). 

While humane organizations were forming all over the United States, the Women’s Branch of the Pennsylvania SPCA—later the Women’s Humane Society—was the first facility to provide humane treatment and a humane quick and painless death to the animals in its care (Zawistowski & Morris 2004). 

With time, the treatment of the animals at shelters improved and following the model of the Women’s Humane Society, strays were no longer killed by drowning.  The concept of dog licensing was first introduced in 1866, in Chicago and the first license tags in 1877, in Dodge City, Kansas.  The fees collected from the licenses were then used to provide salaries for the men who worked at the animal shelter.  Since the workers were on salary and were not dependent on redemption fees like the poundmasters, stealing animals was eliminated and workers concentrated on the capture of strays.  They also made it a point to include cats as part of their efforts, the first time that cats became more than an incidental part of the pound/animal shelter (Zawistowski 2008). 

Of the almost 74 million dogs and 91 million cats that share our homes, 16 percent and 19 percent, respectively, came from an animal shelter.  There are between three and five thousand animal shelters in the United States, with an annual intake of five to seven million animals.  Of those intakes, two to three million are adopted, three- to four-hundred thousand are returned to their owners and three to four million are euthanized (Zawistowski  2008).

Ties to the Philanthropic Sector
Animal shelters, whether municipal with non-profit arms or private non-profit agencies, rely on donations from the public to do their important work.  Shelters, at a minimum provide a place for lost or abandoned animals to find homes.  Many provide humane law enforcement services, behavioral evaluations, remediation and enrichment, health and spay/neuter services, humane education and much more.   

Key Related Ideas


  • Euthanasia Methods.  The early efforts of animal sheltering focused on the humane treatment of animals and finding humane methods of killing those animals that were not placed in homes.  One of the early methods of euthanasia was by clubbing and drowning.  Gas chambers were then employed and provided a death by asphyxiation.  Carbon monoxide is still used in a number of animal shelters to euthanize animals.  Electricity was also used as a mode of euthanasia.  Eventually, death by a lethal injection of sodium pentobarbital became the widely accepted form of euthanasia.  Though lethal injection has become the most common method of euthanasia, there is still controversy.  The American Veterinary Medical Association (AVMA) emphasizes the importance of the collaboration of shelter staff and veterinarian in the proper training in the administration of the lethal injection.  Though lethal injections is commonly used, some communities still permit the killing of unwanted dogs and cats with carbon monoxide derived from engine exhaust, gunshots, and other less humane methods (Zawistowski & Morris 2004). 



  • Pet Population.  The question of “how many” animals were in a shelter did not really become an issue until the last third of the twentieth century (Zawistowski & Morris 2004).  Today, various estimates put the number of pet dogs at about 73.9 million and the number of pet cats around 90.5 million.  Unfortunately, many pets leave their homes each year. They are taken to animal shelters, are placed in another home, or are set free as strays. Presently there are no national reporting agencies for animal shelters though projections would put the numbers in the range of 5-7 million dogs and cats entering shelters annually and the number euthanized estimated at 3-4 million (Zawistowski 2008).

Important People Related to the Topic



  • Caroline Earle White--In an era when it was unusual for women to be in the forefront, she played a prominent role in the formation of the Women’s Branch of the Pennsylvania SPCA in 1869.  In 1874, in response to the horrific treatment of the dogs and cats at the Philadelphia pound, the society built and dedicated the City Refuge for Lost and Suffering Animals.  It was the first facility to provide humane treatment of animals by providing medical treatments, adopting them into new homes and providing them with a humane death (Zawistowski and Morris 2004).   



  • Phyllis Wright of the Humane Society of the United States played an important leadership role in the humane treatment of animals.  She emphasized that companion animals would benefit most from the efforts that combined legislation to provide laws that protect animals, education on the responsible and proper care of animals, and sterilization to reduce the numbers of unwanted animals (Zawistowski and Morris 2004).

Related Nonprofit Organizations

  • The American Humane Association (AHA), founded in 1877, brings together leaders in the animal community to share ideas and information and support joint action on range of issue important in animal welfare (Zawistowski 2008).  AHA offers an array of training courses in animal rescue, certification in euthanasia, humane education and various other topics.  AHA also oversees the treatment of animals that appear in films and televisions. 


  • The Humane Society of the United States (HSUS) is the sponsor of the largest animal conference, Animal Care Expo which brings together animal shelter professionals, veterinarians, behaviorists, experts in fundraising, and others in animal welfare.  HSUS also provided consultation and evaluation services for animal shelters.  HSUS also provides others resources such as Animal Sheltering, a monthly publication for animal shelters and Pets for Life program which offers behavior tips and problem-solving skills to keep pets with families.


  • The National Animal Control Association (NACA) was formed to support the movement toward more professional animal control management (Zawistowski 2008).  The association sponsors the NACA Training Academy, an annual conference and NACA News, a bi-monthly newsletter.  The academy formalizes the skills required by an animal control officer. 


  • The American Society for the Prevention of Cruelty to Animals (ASPCA) in 1995 did not renew their animal control contract with New York City.  It created a National Shelter Outreach department to provide training and assistance for animal shelters around the country (Zawistowski 2008).


  • The Society of Animal Welfare Administrators (SAWA) was formed in 1970, as a way to share information and ideas among the executives who run animals shelters (Zawistowski & Morris 2004).

Related Websites


  • The American Society for the Prevention of Cruelty to Animals (ASPCA®)

Bibliography and Internet Sources

  • ASPCA Animalessons® Animal Shelter 411
  • ASPCA Animalessons® Pet Overpopulation: Behind the Numbers 
  • Fekety, S. 1998 "Shelters." Encyclopedia of Animal Rights and Animal Welfare, M Bekoff and C Meaney Eds. p315-317.
  • Zawistowski, Stephen, Companion Animals in Society. New York: Thomson Delmar Learning, 2008.  ISBN: 9781418013707
  • Zawistowski, Stephen and Morris, Julie. “The Evolving Animal Shelter.” Shelter Medicine Book for Veterinarians and Staff edited by Lila Miller, D.V.M., and Zawistowski, Ph.D., C.A.A.B. 3-9. Boston: 2004. ISBN: 0813824486