Your dog is lost! Following is a timeline of action for the owners. Keep this emergency guide on hand in case your pet is lost.

[edit] Steps

Try and remember if you have had a micro chip installed inside your dog. If you do, you can notify your vet and locate your dog's location in a matter of seconds.
Don't waste time! Get a couple people to work in an organized way simultaneously. In the first two hours, ask family and friends to search around town and up to a two-mile radius of the location where the dog was last seen. Tell any children you see that you are looking for a dog and posters will be up tomorrow with your phone number.
While you are out searching, bring along your dog's favorite toy, or another noise that makes him come running. Dogs can hear sounds from very far away and may come if they hear a comforting sound! Shaking a treat bag or something else a dog knows means food can help, too.
While you're out searching, have someone else make phone calls to your local Humane Society, animal shelters, rescues, vets, and police departments. Contact your neighbors to be on the lookout. If you're close to a county line, contact similar places in that county, too.
Put articles of clothing or a dog's favorite toys outside the house. Dogs are attracted to things that bring them comfort. A scent of their master whom they love can allure them.
If your local TV and radio stations make community announcements, ask them for help.
Notify the local pounds and shelters. If someone does find a dog and brings it there, they will know to reach you. NOTE::: If they do call with a dog that matches, make sure to VISIT YOURSELF. Their description and yours can easily vary.
Check all the pounds in the area. Dogs are sometimes brought in as strays.
Ask the people around your block to be on the lookout for your pet.
Dogs tend to wander where they go frequently or are familiar with. Be sure to put extra flyers around that playground, or notify the owners of that dog park.
Same evening after it's too dark to search any more: Create an ad with a recent picture of your dog. If you don't have a photo, and your dog is a purebred, use a picture from a book. Describe the dog so an average person would recognize him if he saw him. Include identifying information about him like his collar, dog tags, tattoo, identifying features like scars or unusual colorations, or microchip ID number.
Be specific: "LOST: (Dog's Name) a brown dog with white face and paws, SPAYED female; 60#, got loose from yard on Dec. 1, 2005 (Location where lost) near the post office in Our Town, PA around 4 p.m. Wearing a pink collar with rabies tag and license. Is on anti-seizure medication. Family pet. REWARD. Call (610) 555-0000."
It is a good idea to make a few copies of flyers in different languages, like spanish or french, especially if you live in an area with people of many different backgrounds.
Check the "found" ads in they newspaper each day your pet is lost.

WARNING: Never respond to a found pet claim alone. Take a friend and ask to meet in a public place such as the park.

Day 2: Intensify the search. Make at least 200 photocopies of your ad. (Printer ink runs in rain; photocopier toner won't.) Start posting on bulletin boards and in high visibility areas like gas stations and grocery stores in your neighborhood. Tape flyers to phone poles. Ask friends and family members to distribute flyers door-to-door.
After 2 days: Extend your search. Go a little farther by vehicle and start spreading the word to your local mailmen, UPS and Fed Ex drivers, joggers, runners, bikers and anyone else walking around the search areas.
Call area shelters and give them a detailed description of your pet. Drop off or fax a copy of your ad. Expand the radius of your search area by several miles - call shelters even beyond the area you think your dog could have reached.
Start visiting the animal shelters and rescue leagues to look for your pet every other day. Don't expect volunteers to recognize one brown dog from another. If the dog is a dirty, matted mess that lost weight, you may have trouble identifying your own pet. Ask if there is a quarantine area or an area where injured animals are kept in case your dog is separated from those shown to the public.
Last list your pet on helpful sites like www.findingyourpet.com

WARNING: Never respond to a found pet claim alone. Take a friend and ask to meet in a public place such as the park.

[edit] Tips

Check Lost and Found pet sites like www.findingyourpet.com and FindToto.com
Plan ahead for a "lost dog" emergency. Always have a picture of your dog on hand and a record of his ID tag, tattoo license numbers, and/or microchip ID information.
The best defense is prevention, be wary about things such as: open doors, weak screen doors, and other things, beware the frayed leash!!
Keep identifying tags on the dog at all times when outside. Consider a tattoo or a micro-chip that vets and local animal shelters can find with a scanner.
Keep these phone numbers handy: your vet, the animal rescue league, the Humane Society and animal shelters in your county and possibly a neighboring county, local radio or TV stations that make community service announcements, local and state police.
Some people tell you not to put the dog's name on its tag or dog thieves might easily lure the dog into their car. Anyone close enough to read the name tag is probably already holding the dog's collar. It is very difficult to call for a dog without a name. "Here doggy" just doesn't cut it for most dogs who are frightened and are often afraid of strangers.
A reward tends to motivate people. However, don't state an amount. If you make the reward too large, like $5000, people will wonder about the dog's value and some people may not want to return your pet.
Always say a female is spayed, whether she is or not. Again, this is to protect the dog from the unscrupulous who might see a breeding opportunity.
The same logic applies to a medical problem or genetic defect. People will be less likely to think of breeding a dog that could be perceived as valuable if they think it has a medical problem. That gives an urgency to the ad, too.
FAMILY PET tends to motivate people to look. Advertising it as a "show dog," "breeding dog," "therapy dog," or "search and rescue dog" is not a good idea. Too much disclosure is not always the best policy in these matters.
Don't give up too quickly. Dogs have been re-united with their owners even after a year or more. Keep going back to the shelters showing pictures of your dog.
Speediness and thoroughness are essential for bringing your dog home safely.
Look in the area between home and another location the dog knows well - a past home or a place you go together often, perhaps a favorite park.
Search for your dog on Fido Finder.
If you have a purebred dog, check with the rescue organizations for your breed. Many of them have "Lost Dog" links on their websites. Some rescuers will travel a distance to help their breed in need.

[edit] Warnings

Use tape to post on phone poles. In many places, it is illegal and unsafe to use staples because it's a danger to pole men.
If the dog is friendly, say "Please try and coax her into your garage or fenced yard and call us." If the dog is not friendly or could be a fear biter say, "Don't attempt to corner her. Simply call us with her location ASAP."
Leave something out of the description. At this devastating time, you are vulnerable and there are unethical people who may try to take advantage. If someone calls and describes your dog from your ad and says, "I've got your dog here," respond, "Does she have a black mark inside her right leg?" and they say, "She sure does" and your dog doesn't, hang up quickly. You don't want to deal with such people. If they say, "No, she doesn't" and you think it could be your dog, simply say you made a mistake, that is your other dog. Ask another question like, "Does she have a white left paw?" If "Yes," and that's true, try saying her name over the phone and get the dog to react.
If someone tries to blackmail you into a higher reward before returning your dog, try to make sure they have the right dog (or any dog at all) and ask the person to meet you in a public place. Then go with another person to meet them. Don't be taken advantage of. If it is your dog, offer a token reward.
Recent scams include people calling for out-of-state airfare for your lost dog. They might say your dog has been stolen and dumped far from home and they found him 200 miles away. Don't fall for it.
Don't approach young children to ask for their help unless they are family friends. Many children have been warned that this is a trick used by potential kidnappers and kids may become frightened.