Under the heading of humane societies, there are animal rescue organizations, dog shelters, cat shelters, and shelters for exotic and farm animals. The Humane Society of the United States (HSUS), American Humane, and the American Society for the Prevention of Cruelty to Animals (ASPCA) are national groups. Many shelters and other nonprofits that have similar names or call themselves SPCA or Humane Society are not related to the national organizations. These humane societies run independently, and many were founded before the national groups.

Humane societies are located in every state in the country, and in large and small towns and cities. Several humane societies, not animal shelters, work on national animal welfare issues. Organizations including the Humane Society of the United States, American Humane, Defenders of Wildlife, International Fund for Animal Welfare, and many others all have offices in the Washington, D.C., area in order to handle state and federal legislation.

Entry-level workers in these departments provide assistance on key projects. Some jobs, which are usually filled by law students, political science students, and anyone interested in working to improve the lives of animals, consist of maintaining and updating Capitol Hill contact lists, delivering documents to Congressional offices, and assisting staff in research.

Working for nonprofit animal welfare agencies in Washington, D.C, as well as other areas around the country, often means working long hours.

Some animal welfare agencies, such as the International Fund for Animal Welfare, employ legal and political experts and scientists working from offices in 15 countries around the world. Many workers at these agencies, from public relations writer to economist, travel a great deal. A scientist based at the company's headquarters may travel 25 to 50 percent of the time.

To find out more about jobs at humane societies and how to prepare for them, go to the careers section of the Humane Society University's website.