Here's some good advice from the Humane Society
http://www.hsus.org/pets/issues_affecting_our_pets/animal_abuse_and_neglect/reporting_animal_abuse_or_neglect.htmlIf you witness animal abuse or neglect, please contact your local humane society, animal shelter, or animal control agency immediately. In most areas, those agencies have the jurisdiction and capability to investigate and resolve these situations. They rely on concerned citizens to be their eyes and ears in the community and to report animal suffering. You can choose to remain anonymous, although giving your name to your humane agency will enable that group to follow up with you when necessary.
You can find the name and number of your local humane society or animal control agency by looking in your phone book's yellow pages under "animal shelter," "humane society," or "animal control," or by calling Information. Often, public animal care and control agencies are also listed under the city or county health department or police department.
You can also find contact information for animal shelters, animal control agencies, and other animal care organizations in your community through web sites like Petfinder.com and Pets911.com.
If there is not a shelter or animal control agency in your community, please report any incident to your police department immediately.
The Humane Society of the United States does not have animal control capabilities; that is a function of local animal control programs. The HSUS is neither legally nor contractually affiliated with—nor is a parent organization for—local humane societies, animal shelters, or animal care and control agencies. In short, The HSUS does not operate or have direct control over any animal shelter.
The HSUS does, however, provide assistance and resources to animal shelters and animal control professionals around the country. We serve as a resource for local animal protection organizations by providing them with educational materials, training opportunities, recommended operations guidelines, and other expertise. And, of course, we conduct large-scale, national investigations covering a host of animal issues.
If you would like more information on animal abuse and what you can do to strengthen animal cruelty laws in your state, please contact us at 2100 L Street NW, Washington, D.C. 20037-1598; 202-452-1100 or check out The HSUS's First Strike campaign.