A common question often posed to Pet Detectives is “If my pet has been missing for a day-month-year can a search dog still pick up a scent?” If the lost pet is a small animal that won’t travel far and you can estimate a specific area where a dog can search, then a cat detection or specific scent dog could potentially be helpful. These two types of search dogs do not attempt to track a scent trail that was deposited by the lost pet. Instead, cat detection and specific scent dogs search for a stationary “scent cone” or the cloud of scent that would be coming off of the animal. This “area search” method is how bomb dogs and drug dogs are used. They don’t track the scent of bombs or drugs but instead they just detect scent. In the same way, cat detection dogs don’t attempt to follow a scent trail but instead they attempt to detect the scent of a cat. Many dogs are also trained in tracking decomposition scents so that if your cat is suspected to be dead after being lost for a month, they can likely assist in the recovery and bring closure. If your pet is a dog that’s been missing for a month, the scent trail is probably no longer there for a search dog to track and follow. How long is scent viable? The truth is, scientifically, no one knows for sure. Estimates based on prior successes worked by search dogs can be made. The majority of successful scent trails that have been worked reveal that the oldest successful trails are about ten to twelve days old. In general, most search-and-rescue trailing dogs are unable to do accurate work on scent trails that are older than seven days. It’s important to keep in mind that scent trails in residential areas that are contaminated with other animal scents, people scents, and auto traffic are more difficult to work compared to a week old scent in a cool, damp forest. Scent has a better chance of surviving in dark, damp, and cool areas compared to open ground on pavement. Scent can also be moved or destroyed by wind currents, passing cars, and sunlight that dries it out.