If you’re researching animal rescue organizations, a good starting point is the largest national animal welfare groups, major animal shelters, and large-scale dog and cat rescue networks.
One important distinction: some organizations rescue animals directly, while others focus on sheltering, adoption, disaster response, veterinary care, or supporting local rescue groups.
1. Major national animal rescue organizations
These are some of the largest and best-known organizations in the United States, especially for dogs, cats, and broader animal welfare.
1. ASPCA
National animal rescue and welfare organization
Rescues animals from cruelty, supports shelters, provides veterinary care, and assists with disasters. In 2025, it helped more than 70,000 animals find homes through adoption and placement support.
ASPCA+1
2. Best Friends Animal Society
National shelter and rescue network
Works with shelters and rescue groups nationwide to increase adoptions and save dogs and cats from euthanasia.
Best Friends Animal Society
3. North Shore Animal League America
Port Washington, New York
A major no-kill rescue and adoption organization specializing in homeless dogs, cats, puppies, and kittens. It describes itself as the world’s largest and longest-running no-kill animal rescue and adoption organization.
World’s Largest Animal Rescue Org
4. Humane World for Animals
Formerly the Humane Society of the United States
Works to combat animal cruelty, puppy mills, and neglect while supporting animal rescue, disaster response, and animal protection programs.
5. American Humane Society
National animal protection organization
Supports animal rescue and emergency response, animal welfare, and programs that protect animals in disasters. Its 2025 impact report describes work benefiting more than 1.7 billion animals across its programs.
American Humane Society
2. Other large animal rescue and shelter organizations
These organizations operate substantial shelters, adoption programs, or specialized animal rescue services.
| Organization | Location | Website |
|---|---|---|
| Massachusetts SPCA (MSPCA-Angell) | Massachusetts | mspca.org |
| Denver Dumb Friends League | Colorado | ddfl.org |
| San Diego Humane Society | California | sdhumane.org |
| Arizona Humane Society | Arizona | azhumane.org |
| PAWS Chicago | Illinois | pawschicago.org |
| Oregon Humane Society | Oregon | oregonhumane.org |
| Animal Humane Society | Minnesota | animalhumanesociety.org |
| Austin Pets Alive! | Texas | austinpetsalive.org |
| Lifeline Animal Project | Georgia | lifelineanimal.org |
| Michigan Humane | Michigan | michiganhumane.org |
These are prominent organizations, not a strict ranking by the number of animals rescued. Financial size, shelter intake, adoptions, and national reach can produce different rankings. Revenue comparisons identify ASPCA, Humane World for Animals, Best Friends Animal Society, and MSPCA-Angell among the largest animal welfare nonprofits.
PlainCharity+1
3. How large is animal rescue in America?
5.8 million
Dogs and cats entering U.S. shelters and rescues in 2025
4.2 million
Dogs and cats adopted in 2025
13,471
Animal-sheltering organizations counted nationally
597,000
Dogs and cats euthanized in 2025
Source: Shelter Animals Count, 2025 Annual Data Report.
Shelter Animals Count