There’s a good chance you will eventually come across a dog that appears to be lost or homeless. As a dog lover, your first instinct will probably be to help the pooch. Before you take action, there are important safety precautions you should remember.
Err on the side of caution
An unknown dog wandering the streets alone may be ill, confused, scared, or hurt. It may also be a dog that has been abused. All of those conditions can make a dog behave in an unpredictable way. And the situation can also be exacerbated if you are walking your own dog at the time. If your dog starts barking or tries to “defend” you, the other dog—even if he initially appears harmless—may become aggressive or run away. 
Make the right call
For all those reasons, it is often best to call your local police or animal control professionals. They are the experts at dealing with homeless and lost dogs. Thanks to their training, they can quickly ascertain if the dog has recently wandered away from its owner or has been a homeless wanderer for some time. And they know the best techniques for approaching and capturing the dog.
It’s always a good idea to program the phone number of your local animal control department into your mobile phone’s contact list. Once you’ve called them and provided the dog’s location, you may want to keep an eye on the dog from a safe distance. That way, you can call animal control to give them updated information about the dog’s location if he starts wandering.
Acting on your own
If you cannot contact the animal control office and if the dog seems harmless, docile, uninjured, and approachable, you still need to exercise good judgment and caution.
Approach slowly. Scaring a dog by making sudden or fast movements may provoke him into an attack or cause him to run away, perhaps into traffic.<a
Stay calm and speak in quiet tones. Try to act in a reassuring way, soothing the dog with a friendly demeanor.
Offer food or a treat. This may motivate the dog to meet you half way by coming to you and showing that he trusts you.. Besides, if he’s been wandering around for awhile he may be hungry.
Check to see if the dog has tags. 
If the dog has tags, there’s a good chance he’s simply lost and not a dog that’s been roughing it on the streets all his life. And the odds of the dog being trained and accustomed to human contact go up. If you have a nylon lead with you, gently slip it over the dog’s head to keep him from running away. This should also make it easier for you to check his tags. They may have contact information for his owners or other useful info to help you identify where he lives. You may be able to call them right away and, if all goes well, witness a happy reunion very quickly.
If you live nearby and the dog is willing to go with you to the safer environment of your home, place him in an area where he feels comfortable. And keep him separated from your own pets—preferably in a gated yard—to avoid territorial disputes and the possibility of the lost dog transferring parasites or diseases.
Now that the lost dog is in a safe place and getting the attention and reassurance he needs, you should take the following steps to help reunite him with his owner:
- If you haven’t already done so, check his tags for contact information.
- Call your police and animal control departments, as well as local animal shelters, and notify them about the dog. If the owner has been searching for the dog, they may have notified at least one of those organizations.
- Take the dog to an animal shelter or local veterinarian to see if he has an identification microchip.
If those efforts don’t reunite the dog with its owners, you can:
- Post FOUND DOG messages in local newspapers. People who have lost dogs often read these notices to see if any description matches their beloved pet.
- Place FOUND DOG posters and flyers in popular areas around town. Make sure your posters and flyers have the dog’s photo and your contact information.
- Spread the word to all your local dog-loving friends. Use email, phone calls, Facebook posts and Tweets to get the word out. Use a photo of the dog wherever you can. In today’s social-media era, it’s easy for these messages be shared. The ever-widening net of contacts may eventually reach the owner or someone who knows the dog.
What to do if someone claims the dog
Never simply hand the dog to a person who claims the dog his theirs. The fact is, you never know if this person is being honest when they say, “He’s mine. Oh, how I’ve missed him.”
In addition to asking for the person’s identification, make sure they can prove the dog is really theirs. This can take the form of photos of them with the dog—we all have tons of photos like this—or official documents that list the dog’s breed/description and age.
And here’s another simple thing to try: See how the dog reacts when he see’s the purported owner. If he runs up and give him a lick, that’s a good sign. But if the dog is indifferent or backs away in fear, you should be leery. If the person insists the dog is theirs but you still have your suspicions, call your local police department.
Article credit – www.pedigree.com