National Shelter Directory. Searchable database of nearly 5,000 community SPCA's humane societies and animal control agencies.
The Humane Society of the United States’ Safe Cats Campaign
Wildlife Society's Policy Statement on Free-roaming Cats
Municipal Code Corporation Web site. Search animal welfare legislation by state and county.
Urban cat predation studies by Carol Fiore. Both technical and non-technical articles.
Several national veterinary associations advocate keeping cats indoors: Association of Avian Veterinarians, the Alliance of Veterinarians for the Environment, and the American Veterinary Medical Association
Hawaii Cats Indoors Website developed by ABC for the Hawaii Department of Forestry and Wildlife
Florida Cats Indoors! Stewardship Materials. Produced by the Florida Fish and Wildlife Conservation Commission, in conjunction with ABC.
Ohio State University College of Veterinary Medicine’s Indoor Cat Initiative
National Audubon Society: Reducing Threats from Cats
CA Fish and Game - Cats and Wildlife Pages.
The Canadian Federation of Humane Societies’ Happy Indoor Cats page
Habitat Haven - manufactures products that let your indoor cat go outdoors safely.
Feline Funhouse - Portable outdoor cat enclosures.
Safe Kitty - Permanent outdoor cat enclosure structures.