An animal shelter or pound is a place that stray, lost, abandoned or surrendered animals, mostly dogs and cats and sometimes sick or wounded wildlife, are kept and rehabilitated. While no-kill shelters exist, it is sometimes policy to euthanize animals that are not claimed quickly enough by a previous or new owner. In Europe, of the 30 countries included in a survey, all but five (Austria, Czech Republic, Germany, Greece and Italy) permitted the killing of healthy stray dogs. Critics believe the new term "animal shelter" is generally a euphemism for the older term "pound".
The word "pound" has its origins in the animal pounds of agricultural communities, where stray livestock would be penned or impounded until they were claimed by their owners.
United States and Canada
In the United States there is no government-run organization that provides oversight or regulation of the various shelters on a national basis. However, many individual states regulate shelters within their jurisdiction. One of the earliest comprehensive measures was the Georgia Animal Protection Act of 1986, a law enacted in response to the inhumane treatment of companion animals by a pet store chain in Atlanta. It provided for the licensing and regulation of pet shops, stables, kennels, and animal shelters, and it established, for the first time, minimum standards of care. The Georgia Department of Agriculture was tasked with licensing animal shelters and enforcing the new law through the Department's newly created Animal Protection Division. An additional provision, added in 1990, was the Humane Euthanasia Act, the first state law to mandate intravenous injection of sodium pentothal in place of gas chambers and other less humane methods. The law was further expanded and strengthened with the Animal Protection Act of 2000.
Currently, it is estimated that there are approximately 5,000 independently-run animal shelters operating nationwide. Shelters have redefined their role since the 1990s. No longer serving as a lifelong repository for strays and drop-offs, modern shelters have taken the lead in controlling the pet population, promoting pet adoption and studying shelter animals' health and behavior. To prevent animal euthanization, some shelters offer behavioral assessments of animals and training classes to make them more adoptable to the public. Most shelters also provide medical care that includes spaying and neutering to prevent overpopulation.
Shelters and shelter-like volunteer organizations responded to cat overpopulation with trap-neuter-return (TNR) programs, which reduced feral cat populations and reduced the burden on shelters.
In the United States, many government-run animal shelters operate in conditions that are far from ideal. In the wake of the financial crisis of 2007–2008, many government shelters ran out of adequate space and financial resources. Shelters unable to raise additional funds to provide for the increased number of incoming animals have no choice but to euthanize them, sometimes within days. In 2012, approximately four million cats and dogs died in U.S. shelters. However in recent years, there has been a dramatic drop in the number of animals euthanized in shelters, due mainly to a successful push to promote spaying and neutering of pets. 
In Quebec, there are two types of animal shelters:
- SPCA (in French, 'Société pour la prévention de la cruauté envers les animaux')
- SPA (in French, 'Société protectrice des animaux')
In the United Kingdom, animal shelters are more commonly known as rescue or rehoming centres and are run by charitable organizations. The most prominent rescue and rehoming organisations are the RSPCA, Cats Protection and the Dogs Trust.
Larger cities in Germany have a city shelter for animals or contract with one of the many non-profit animal organisations in the country, which run their own shelters. Most shelters are populated by dogs, cats and a variety of small animals like mice, rats and rabbits. Additionally, there are so-called Gnadenhöfe ("mercy-farms") for larger animals that take cattle or horses from private owners who want to put them down for financial reasons.
The Animal Protection Act the prohibits killing of vertebrates without a proper reason. Generally, proper reasons are slaughtering or hunting for food production (cats and dogs are excepted from that), control of infectious diseases, painless killing "if continued life would imply uncurable pain or suffering" or if an animal poses a danger to the general public. The latter will be a reason for euthanasia only if an authority concerned with public safety orders it based on an investigation. Because of the ruling, all German animal shelters are practically no-kill shelters. Facilities must be led by a person who is certified in the handling of animals. Most shelters contract veterinarians to provide medical care.
Across India, various animal shelters are run by animal lovers. The Lal Mandir, a prominent Jain temple in Delhi, is known for the Jain Birds Hospital in a second building behind the main temple. Blue cross of India and PETA India are the major animal rescue organizations in India
Land of the Strays, 152-hectare sanctuary in the centre of the Central American country is funded by donations. Around 8,000 dogs have passed through the refuge.
United Arab Emirates
Some popular shelters in the United Arab Emirates (U.A.E) are K9 Friends, Ras Al Khaimah Animal Welfare Centre (RAK AWC), Sharjah Cat & Dog Shelter and Abu Dhabi Animal Shelter. There are many other private shelters, rescue groups and pet adoption groups within the U.A.E.
- Abandoned pets
- Black dog bias
- Cat colony
- Dog camp
- Goshala, cow shelters in India
- No-kill shelter
- Overpopulation in companion animals
- Pet adoption
- Shelter Dogs, a controversial 2003 documentary film
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