Legal hold periods vary across the country, with some as short as 72 hours. This is why it is critical to identify the shelters that serve your area and to visit them in person as soon as possible.
The shelter jurisdiction system is complicated and confusing. Start by calling or visiting the shelter nearest you or the one with which you are familiar. If you aren't familiar with any shelters, start with your local law enforcement: police, sheriff, etc. as they sometimes handle animal control . Even if they are not involved in animal control, they should know where to send you to look for your missing pet.
Be aware that there may be multiple shelters serving your area; for example, one shelter may serve the unincorporated area while another serves the city. Animals don't recognize boundaries and may wander into another jurisdiction, especially dogs that typically travel farther than cats. Because of this, it is important to regularly check every possible shelter that may have picked up your pet. A Missing Pet Consultant can help you sort this out, and some will check shelters for you.
While we encourage shelters to take lost reports over the phone, they are not often effective for several reasons: one, your description of your pet may differ from theirs, and two, shelter staff often don't have time to check these reports. Owners should visit the shelter(s) in person at least every 2-3 days, and bring a clear photo for the lost report.
Animal shelter staff have difficult jobs and are often subject to verbal abuse from the public. While it is appropriate to ask about hold periods, policies and procedures, and other subjects relevant to your search, do not ask staff, "When do you kill the animals?" or make similar inflammatory remarks. Be kind and respectful and, as in any other place of business, the staff will be more likely to go the extra mile for you.
Some owners don't check the shelter because they believe they will get a call since their pet is microchipped. First, up to 50% of microchips in impounded pets in the U.S. are not currently and correctly registered. Second, the system is not foolproof, and a low battery or improper scanning technique can cause a chip to be missed. Don't take a chance and wait for a call -- go to the shelter and search in person. Call the microchip company to report your pet missing and to update the contact information. If you're not sure which company to call, enter the chip number in Pet Microchip Lookup in the U.S. Similar sites exist in other countries -- search for "pet microchip lookup."