Summarize this article in one sentence.
Recognizing abuse is not always easy. Aggressive, timid, or skittish behavior can be but is not always an indicator of abuse. The best way, according to ASPCA's experts, is to observe animal’s treatment by its owner and its surrounding environment. Examples of typical abuse include.  Physical signs of cruelty  Wounds on the body or signs of injury not being treated Patches of missing fur/hair. Limping, weakness, or the inability to stand or walk normally An owner striking or otherwise abusing an animal Overly tight collar embedded in the animal's neck Visible signs of confusion or extreme drowsiness   Environmental signs of abuse  Pets that are left repeatedly alone without food/water, often chained Pets that are kept outside without shelter in extreme weather conditions Pets kept in an unsanitary enclosure Animals kept in cages or kennels that are either overly crowded or too small   Signs of neglect  Tick or flea infestations left untreated Extremely thin/starving animals Signs of inadequate grooming, poor coat condition, extremely long nails Heavy discharge from eyes or nose Animals that show signs of injury but have not been taken to a veterinarian Every locality has different laws or agencies that deal with animal abuse. Do some research online or simply in the telephone book to find some of your options. You may also contact your own veterinarian to find out what agencies are available in your area.  Some examples to look for:  Local police. Either call the main non-emergency desk number or find out if there is a separate animal control officer. Do not call the emergency 9-1-1 number unless there is an actual emergency. Your county District Attorney’s office. You will often find there is a special department assigned to crimes against animals.  Society for the Prevention of Cruelty to Animals (SPCA). This is a national organization, but there are state branches that include the name (and initial) of the state:  MSPCA – Massachusetts Society for the Prevention of Cruelty to Animals  NJSPCA – New Jersey Society for the Prevention of Cruelty to Animals Check the Internet for your state or local branch of the SPCA.   Humane Society Other online sources – just do a general search online for “Animal abuse in [your state].” This should give you plenty of options. If possible, try to get photographic, video, or other recorded evidence of the abuse happening. If you can, try getting written/factual statements from other witnesses. If not, write down everything you know, witnessed, or think you know about the abuse. Concise/factual details/dates will be valuable. Be careful not to put yourself in danger or break any laws. You should not trespass or enter another's property without permission. Not only is this illegal but you could assume that the owner who is committing the abuse could be just as dangerous toward you as he or she is to the animals.

Summary:
Be aware of possible signs of abuse. Research local animal care agencies. Collect evidence.