Cross posting with permission:
Brown Dog Foundation-for pet owners whose pet faces a treatable life-threatening condition
Care Credit-for pet owners to apply for credit to pay vet bills
Feline Veterinary Emergency Assistance Program-for cat owners
Good Samaritan Fund-for pet owners
Grey Muzzle Organization-for shelters and rescues, to help senior dogs
Help-A-Pet-for pet owners
IMOM-for pet owners and rescues
Neuter and Spay-low cost spay/neuter programs worldwide
The Pet Fund-for pet owners who can't afford vet care
Pet Lovers Online-Financial Aid in the UK
Protect My Pet-low cost vaccination clinic
Shakespeare Animal Fund-for pet owners who can't afford vet care, focusing on seniors
Spay USA-low cost spay/neuter programs throughout the US
United Animal Nations-for rescues and owners
Veterinary Care Partnership Program-for IIADP assistance dogs
Actors and Others for Animals-helps pet owners in the LA, CA area
Animal Assistance League of Orange County-for elderly, disabled and low income pet owners
Animal Guardian Society-for elderly and low income pet owners in Southern California
Marin Humane Society-provides financial aid and dog food for elderly, those with HIV/AIDS, and those in hospice
Orange County SPCA-has an Animal Rescue Fund to help low income pet owners pay for veterinary care
Pet Orphans of Southern California-helps low income families pay for veterinary care
Pets in Needlow and no cost veterinary care for needy San Mateo and Santa Clara County residents
Sue Freeman's Guide to Rescue Cats-list of sources of financial aid for pets in the LA area
Spay Neuter Animal Network-Helps pet owners with vet care and offers low cost spay/neuter vouchers in Ventura County area
Sacramento Area Animal Coalition-low cost spay/neuter in the Sacramento area
Sacramento SPCA-low cost spay/neuter
Spay California-low cost spay/neuter programs in California
Maxfund-Low cost veterinary clinic in Denver
SPCA of Central Florida-low cost spay/neuter clinic
Save Our Strays Atlanta-low cost spay/neuter clinic in Atlanta GA
FACE Spay Neuter Clinic-Low cost spay/neuter clinic in Indianapolis, IN
Massachusetts:
MSPCA SNAP Program-low cost spay/neuter throughout Mass.
The Sampson Fund-for pet owners who can't afford vetwork for their critically ill animal
Maryland
Frederick County SPCA-financial assistance for vet care for pet owners, low cost spay/neuter
Minnesota:
Medipet-spay/neuter and emergency vet care funding for low income pet owners
Missouri:
Humane Society of Missouri-low cost spay/neuter program
Operation SPOT-low cost spay/neuter program
New Jersey:
STAF-financial assistance for vetwork for pet owners
New York:
Lollypop Farm-financial assistance for senior citizens, low cost spay/neuter in Monroe County
Dove Lewis Velvet Assistance Fund-helps low income pet owners with emergency vet care, in Portland
Rhode Island:
Rhode Island Companion Animal Foundation-provides funding for vet care for pets with low income owners
Rhode Island Veterinary Medical Association-list of organizations that offer financial assistance with vet bills
Volunteer Services for Animals-information on low cost spay/neuter programs
Texas:
Capper and Chris Save the Animals Fund-helps pet owners with veterinary bills, in College Station
Utah:
Humane Society of Utah-low cost spay/neuter and vaccination clinic
Virginia:
Animal Welfare League of Arlington-low cost spay/neuter and vaccinations, offers loans for vet bills
Partners among Cats and Canines-financial aid for spay/neuter and vetwork
Budkis Fund-helps seniors pay for emergency vet care
Concern for Animals-helps owners pay for spay/neuter and vet care in Thurston, Mason and Lewis County area, pet food bank
PAWS of Bainbridge Island-free and low cost spay/neuter program
Washington State University Good Samaritan Fund-helps pay for treatment at WSU for pets whose owners can't afford treatment
Washington Animal Rescue League-helps low income pet owners with veterinary care
Assistance for pet owners of specific breeds:
Doberman Pinschers:
Doberman911-helps owners with vet bills for senior or special needs Dobermans
Great Pyrenees:
Pyramedic-helps owners and rescues with vet bills for Great Pyrenees
Labrador Retrievers:
Labrador Harbor-for owners of Labrador Retrievers
Labrador Lifeline-for owners of Labrador Retrievers
Labmed-for rescued Labrador Retrievers
Pit Bull:
Pit Bull Rescue Central-for Pit Bull owners
Cats in Crisis-for cat owners and rescues
CorgiAid-helps Corgis in rescue
IMOM-for pet owners and rescues
Labmed-for Labs in rescue
Labrador Harbor-for Labs in 501(c)(3) rescues
Pyramedic-helps owners and rescues with vet bills for Great Pyrenees
SOS-SRF-for Siberian Huskies in rescue
Assistance for specific conditions: