Search dog handlers often joke that good search dogs make terrible house pets. There is some truth to this. A good search dog is what dog people call “high drive”. A dog that wants and needs to work. A dog that is insanely focused on task and has a lot of energy. In general these dogs aren’t the greatest pets. If they don’t get a job they make up one for themselves!
Watch 11 week old Bax doing a footing exercise: Bax USAR alley.
We don’t have any breed biases. If a dog has the right drive and wants to do the job, is physically and mentally able to do the work, we don’t care if the dog is pedigreed or 
what type it is or what breed group it belongs to.
We’re looking for energetic dogs that have some form of usable reward system. Dogs that are crazy about tug toys or their ball on a rope. Dogs that will work for a prolonged amount of time to find their toy even in difficult terrain (navigating uneven, unstable and moving ground, black berries, wet surfaces…). 
Medium to large sized dogs work best. The dog needs to be big enough to safely navigate rubble, slash and ladders and needs to be light weight and sporty enough to clear obstacles and work for long hours on rubble, slash or in wide area searches.
Disaster search dogs not only need to be physically sound they also need to have the temperament to match! Working in loud and hectic environments, traveling via airplane, buses and helicopters to training and deployments, being in close proximity to other dogs, humans and sometimes wild life are just a couple of things a disaster dog needs to deal with. Because of this there can be absolutely no real aggression towards other dogs or people!
Most of our team mates prefer getting a purpose bred puppy from a working dog breeder. A good breeder does extensive health testing, picks the right working dogs to breed and will give the puppies the appropriate socialization to prepare them for their demanding job.
Some members opt for getting a rescue or second (sometimes third or even more) hand dog. Most often a former pet dog that was too much to handle for the previous owner. A dog that needed a job and had the right drive to become a search dog. Often these dogs are at least a couple of months old. The benefit of getting an older dog is that an experienced handler or trainer already gets a very good idea of drive, nerve strength 
and work ethic hence they can make a good educated guess if this dog will be successful in becoming a disaster search dog or not.
Not all dogs make it as disaster search dogs. Successful disaster search dogs that can pass the rigorous testing are an elite group. Some dogs do better as active pets or sport dogs and not every dog that is “high drive” has the nerve strength or the temperament to be a USAR search dog.