If you suspect that an animal has been abused, by someone you know or by a stranger, there are things you can do. The most important act you can take is to report the cruelty to your local law enforcement. In some cities, this may be animal control or a department of Humane Law Enforcement, while in other areas the police or sheriffs department may be the agency in charge of these sorts of crimes.
If you are unsure of who to contact, try your local yellow pages, or you can use the ASPCA's Humane Law Enforcement Lookup page to locate the agency in your area. You can also check the front section of your telephone yellow pages and search for Animal Control.
Some areas (especially more rural parts of the country) may not have a designated Animal Control Department, in which case there may be a an branch of a local humane society that has been assigned the power to investigate cruelty cases. If your city does not have an animal control or humane law enforcement department, cruelty cases may fall under the jurisdiction of the sheriff's department or local police.
If you witness animal cruelty in progress and do not know the number to the appropriate agency, CALL 911. Animal cruelty is a CRIME, and the police dispatcher will be able to determine which department should respond.
Repeat offenses of animal cruelty crimes are a rule, not an exception - and there are many times when an investigation into an animal cruelty crime uncovers human-related crimes as well. When officers go to the home to investigate an animal cruelty issues, they often find evidence of domestic abuse, child neglect, drugs and other dangerous situations. Reporting animal cruelty could save a human life.
When a violent crime is committed against anyone you love, there is always a flood of emotions: anger, outrage, hurt, worry, helplessness... Your pets are no exception, and when someone deliberately causes them harm, the reaction isn't much different than if they had attacked a human family member. The fact is, there are some things you can do. Animal abuse is a crime, and depending on where you live, it can be a pretty serious one.
Do NOT attempt to deal with the crime yourself. The authorities are there to help you, and the sooner they are involved, the better.
For important information on things you can do to help investigators build a better case, visit the documentation page.