Houston area animal shelters:

Citizens for Animal Protection (CAP) - www.cap4pets.org
SPCA - www.houstonspca.org (24-hour injured animal rescue)
Houston Humane Society - www.houstonhumane.org
Harris County Animal Control - www.countypets.com

Houston area rescue and fostering organizations:

Dog Rescue Directory: www.acmepet.com/canine/civic/rescue.html
Homeless Orphaned Pet Endeavor (HOPE) - www.homelesspets.net
Twyla’s Friends - www.twyla.org
Homeless Pet Placement League (HPPL) - www.hppl.org

Cat Rescue Organizations:

Feral Cat Connection: www.geocities.com/spddemun/
Feral Cat Coalition - www.feralcat.com

Livestock and Exotic Animal Rescue:

Houston SPCA - www.houstonspca.org

Rabbit Rescue:

Bunny Buddies Rabbit Rescue - www.bunnybuddies.org

Wildlife Rescue:

Texas Wildlife Rehabilitation Coalition - www.twrc-houston.org