Report Highlights. An animal shelter is a non-profit organization, public or private, that houses and rehabilitates domestic animals. The number of animals entering shelters has decreased in recent decades. While some of the decrease may be due to budget cuts, experts mainly credit public opinion and improved practices, such as population control through sterilization.

  • In all of North America, there are 10,000 rescue groups and sanctuaries.
  • There are 3,500 brick-and-mortar animal shelters in the United States.
  • U.S. shelters take in over 6 million animals every year.
  • About half of shelter animals are adopted.
  • As many as 40% are euthanized, often due to lack of space and funding.
  • In surveys, most people drastically underestimate the number of animals killed in shelters each year.

Statistics About Shelters and Shelter Animals

In the last 50 years, animal shelters across the U.S. have diminished their intake numbers. While little available information predates the mid-20th century, a few numbers are available from the era when public opinion about stray animals and shelters began to shift. More animal specialists have come to recognize the value of record-keeping and statistical analysis.

    • In 1973, shelters took in over 20 million dogs and cats; at that time, it wasn’t uncommon for 90% of shelter animals to be euthanized.
    • By 2020, shelter intake nationwide was down 68%.
    • In the last decade, the number of animals entering shelters has declined by 10%.
    • 49% of shelter animals are adopted; in some states, the adoption rate is as high as 90%.
    • 18 months is the average age of animals entering shelters.
    • Americans spend over $2 billion annually on animal control, shelters, and euthanasia/disposal.
    • 2% of shelter animals die of natural causes.
    • 34% of shelters use behavior modification to make animals more adoptable.
    • 42% of non-pet owners who express interest in getting a companion animal say they would not consider adopting from a shelter.

Pets in Shelters

One out of every three family pets gets lost at some point in their lifetime. It’s unknown how many of these runaways end up in animal shelters or rescues. Caretakers can only estimate based on clues, such as whether a cat has been sterilized or has otherwise been to see a veterinarian.

  • 11% of animals in shelters find their way back to an owner.
  • 30% of shelter animals are relinquished by an owner.
  • 50.2% of shelter animals enter as strays.
  • 10% of animals entering shelters are spayed or neutered.
  • 20% of animals adopted from shelters are returned.
  • Pets outnumber shelter animals 100-to-1.

Euthanasia in Shelters

One side effect of falling shelter populations has been the decrease in incidents of euthanasia. The U.S. Food and Drug Administration (FDA) specifies that euthanasia must be painless. Most states have laws regulating the administration and methods of animal euthanasia; a licensed veterinarian must perform the procedure, for example, and must use an approved agent.

  • 25% of shelter animals are confirmed euthanized.
  • 35 states have laws about how long a shelter must hold an animal before authorizing euthanasia.
  • In states with holding laws, the minimums range from 48 hours to 10 days.
  • 5 states are responsible for half of all euthanized shelter animals.
  • It’s estimated that 99% of euthanized animals are adoptable.
  • As many as 57% of euthanized animals are unweaned kittens.
  • Since 2011, euthanizations in shelters are down roughly 42%.
  • Specialized spay and neuter clinics offer low-cost surgeries, which reduced the population of unwanted pets in one California town by 70%.
  • Shelters that sterilize prior to release reduce intake by 10% over five years.
  • Almost 90% of people surveyed believe euthanasia rates are less than half of what they actually are.
  • Up to 10% of animals in no-kill shelters are euthanized due to health or behavioral reasons.

Facts About Shelter Cats

Cats outnumber dogs in many shelters, sometimes by as much as 3-to-1. Pet cats are more likely than pet dogs to spend time outside alone, and they are much less likely to be reunited with owners. Both in and outside of shelters, it’s not uncommon for cats to form bonded pairs; some shelters offer discounts to encourage adopting bonded pairs together, and in fact, the average cat-owning households has 2 cats.

  • 3.2 million cats live in shelters nationwide.
  • For every cat in a shelter, there are 27 pet cats.
  • 31% of pet cats, or about 26.5 million, were adopted from a shelter.
  • Cat owners are 40% more likely to adopt their pet from a shelter than dog owners.
  • Shelters take in up to 130% more cats during warmer months than they do in the dead of winter.
  • More cats enter shelters as strays than any other animal.
  • Some shelters report euthanizing up to 70% of cats.
  • 2-5% of shelter cats are reunited with an owner.
  • 19% of people say shelter cats are less adoptable than shelter dogs.

Facts About Shelter Dogs

The number of dogs entering shelters is declining at a faster rate than it is for cats. Dog owners are less likely to get their animal from a shelter than cat owners. Some dog breeds are at greater risk than others for euthanasia or long-term shelter stays. For example, smaller dogs are more likely to be adopted and have shorter shelter stays than larger dogs.

  • Nationwide, there are 3.3 million shelter dogs.
  • For every dog in a shelter, there are 26 pet dogs.
  • 23% of pet dogs, or about 17.9 million, were adopted from a shelter.
  • 48% of shelter dogs are adopted.
  • 36% of Americans who choose to rehome their dog take it to a shelter.
  • 22% of shelter dogs are euthanized.
  • 15-20% of shelter dogs are reunited with an owner.
  • 25% of dogs in shelters are purebred.
  • 4 of the 10 most popular dog breeds are also the most commonly found in shelters.
  • Toy breeds are most likely to be adopted at a rate of 73%.
  • Herding dogs are least likely to be adopted at a rate of 48.7%
  • A shelter dog spends an average of 35 days waiting to be adopted.
  • “Black Dog Syndrome” refers to the phenomenon that – according to some studies – animals with dark fur are less likely to be adopted from a shelter than animals with light fur.

Shelter Puppies and Kittens

One thing stray animals have in common is that most of them have not been spayed or neutered. Baby animals are common in shelters, where they are especially vulnerable. Proximity to other animals spreads infectious and viral diseases. The extra attention and care that all babies require is often unavailable due to a lack of resources or knowledge.

  • 42% of shelter cats are kittens.
  • Kittens are 33% more likely to be adopted than adult cats.
  • July through December is “kitten season” in most shelters.
  • Kittens require bottle feedings every two hours and round-the-clock care.
  • 55-71% of kittens that die in shelters are killed by disease.
  • The mortality rate for orphaned kittens is as high as 40%.
  • 46% of shelter dogs are puppies or juveniles.
  • Puppies under six months wait an average of 23 days before they’re adopted.
  • On average, a lapdog puppy spends just 13 days in a shelter before adoption.

Other Shelter Animals

While cats and dogs make up the majority of their animals, shelters generally don’t turn animals away. Many exotic animals have extensive life spans and may spend years living in shelters. Some shelters specialize in one kind of animal that has specific needs and requirements; perhaps that particular animal has a high rate of euthanasia at an average shelter.

    • Dogs and cats are 50% more likely to be adopted than other shelter animals.
    • After dogs and cats, rabbits are the most-abandoned animals.
    • Turtles carry salmonella and require special handling.
    • Shelters have reported taking in dozens of animals species, including, but not limited to:
  • Parrots
  • Turtles
  • Snakes
  • Rabbits
  • Chinchillas
  • Hamsters
  • Rats
  • Dabb Lizards
  • Bushbabies
  • Fish
  • Ferrets
  • Pigs
  • Bearded Dragons
  • Iguanas
  • Emus
  • Peacocks
  • Llamas
  • Gerbils
  • Parakeets
  • Spiders
  • Chickens
  • Cows
  • Horses
  • Goats
  • Guinea Pigs
  • Mice
  • Donkeys
  • Capybaras
  • Sugar Gliders
  • Alpacas

Specialty Shelters

Some animals are highly sought by people for reasons other than companionship, such testing, racing, or illegal activities, such as fighting. These animals are often require rehabilitation before they can be considered candidates for adoption. They may also suffer from specific injuries typical of their industry; the most common injury among racing greyhounds, for example, is a broken leg.

  • 80,000 new greyhounds join the racing industry each year.
  • 3-5% of racing greyhounds injuries are fatal.
  • Injured racing animals are typically “retired.”
  • Over 1200 racing horses experience fatal breakdowns and injuries each year.
  • Horse racing is legal in 22 states.
  • Most states have shelters or sanctuaries just for retired racing animals.
  • Dog fighting has been a felony in all 50 states since 2008.
  • Pit bulls are the most popular fighting dogs in the United States due to their perceived ferociousness.
  • 93% of pit bulls in shelters are euthanized.
  • As many as 100 million animals are held in research laboratories each year.
  • 80-95% of these animals are not protected by laws regulating the care, keeping, transfer, and disposal of animals.
  • Since 2000, a national sanctuary system has taken in chimpanzees used in experimentation.
  • Smaller animals, such as rodents, are almost always die during or immediately after an experiment via euthanasia.

How Animal Shelters Benefit Communities

Veterinarians and similar animal specialists consider animal shelters an essential service in civilized society. Free-roaming animals spread illness and disease through their waste. More troublesome creatures can cause damage to property while vicious and feral animals may attack people.

  • An estimated 140 million stray cats and dogs roam the streets nationwide.
  • Stray cats outnumber shelter cats 22-to-1.
  • At least 98% of stray cats are unsterilized.
  • Theoretically, one unsterilized stray can produce tens of thousands of descendants in a few years.
  • Realistically, one unsterilized stray may produce over a thousand descendants within a decade.
  • 90% of all dogs born will spend their entire lives on the street.
  • Animals living outdoors are prone to multiple diseases they then pass on to humans, including:
    • Ringworm
    • Rabies
    • Toxocariasis
    • Rocky Mountain Spotted Fever
    • Campylobacter Infection
    • Bartonella Infection

The First Animal Shelters

Animal shelters in the modern sense have existed in the United States for over 150 years. The very first was founded by thirty women from Pennsylvania and New Jersey, spearheaded by Caroline Earle White. The organization still exists today under the name Women’s Animal Center.

  • Early animal rights activists, including White, cited Britain’s Royal Society for the Prevention of Cruelty to Animals (RSPCA) as influencing groups in the United States.
  • Prior to 1800, cruelty to animals was not against the law anywhere in the Western world, except in cases where abuse constituted damage to property (the animal being property).
  • The earliest known regulation is from 1821 and prohibited “cruelly beat[ing] any horse or cattle.”
  • The Royal Society for the Prevention of Cruelty to Animals, the precursor to American SPCAs, was founded in 1824.
  • The first American shelter was founded in 1869 by White and other women who were barred from leadership roles in their local SPCAs; such positions were reserved for men only.
  • Almost immediately, the women assumed the duties of Philadelphia’s city pound.
  • Their influence would inspire the formation of the American Humane Association in 1877.
  • White would go on to found the American Anti-Vivisection Society in 1893.

A Warning About Illegal Shelters

The ASPCA has reported an increase in recent years in the number of animal hoarders posing as rescue operations. Some people just have a lot of pets; animal hoarding is a serious psychological condition that is harmful to the animals as well as anyone living in the hoarder household.

  • Cats are the most-hoarded animals, followed by dogs.
  • Almost 100% of animal hoarders re-offend.
  • 72% of animal hoarders are women.
  • Hoarding affects an estimated 250,000 animals each year.
  • Hoarding is characterized by several behaviors.
    • Neglect of the animals themselves (malnourished, filthy, ill, etc.)
    • Neglect of property and household maintenance (dried animal droppings, broken furniture, thick dust, extreme clutter, etc.)
    • Neglect of personal health and hygiene.
    • Denial or a lack of awareness about all of these problems.

If you suspect an animal shelter or rescue to be a case of animal hoarding, please contact your local humane society or city/county authorities.


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  2. HomeAgain Fact Sheet
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  5. How Many Cats Are In American Households?
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  10. Facts About Cats
  11. Black Dog Syndrome
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  15. A Brief History of Dog Rescue: How People Started Saving Man’s Best Friend
  16. Caroline Earle White
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  26. Table of State Holding Laws
  27. Dog Shelter and Adoption Statistics
  28. Michigan Becomes ‘No Kill’ State for Shelter Animals
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  30. What Influences a Dog’s Length of Stay at a No-Kill Animal Shelter?
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  32. 13 Things You Might Not Know About Rabbits
  33. PAWS: Puppies and Kittens
  34. The Ultimate Guide to Pet Adoption: Pet Adoption Myths
  35. 9 Animals You Didn’t Know You Could Adopt
  36. Animal Shelters Have Housed Some Unusual Guests Over the Years
  37. 10 Animals With Better Jobs Than You: Cheesecake the Capybara
  38. Unusual Animals Up For Adoption After Ending Up in AL Shelters
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  43. Infections that Pets Carry
  44. Unmasking the Shelter Dog
  45. Another Reason Not to Buy Puppies From Puppy Mills
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  50. Animals Used in Biomedical Research FAQ
  51. Animals in Entertainment: Horse Racing
  52. Thoroughbred Aftercare Alliance Accredited Organizations
  53. Brief Summary of Animal Euthanasia
  54. Shelter Animals Count: Explore the Data