Non-profit charitable organization founded in 1951 to reduce the sum total of pain and fear inflicted on animals by humans. Site includes information about programs, publications, and news.

International animal and nature organization. News, petitions, campaigns, and an Internet based animal identification system.

International wildlife charity working to prevent cruelty and alleviate suffering. News, educational materials, photos, FAQ, and information about ways for individuals to become involved.

International wildlife charity dedicated to protecting animals from cruelty and exploitation. Includes fact sheets, news, information about current projects, and an online shop.

Conducts and publishes independent research and studies studies into the welfare, care, and treatment of companion animals and their role within society.

A national non-profit animal advocacy organization whose mission is to protect animals in danger or need and to focus global attention on their plight to create a more humane world.