Search dogs climbed through the debris at Ground Zero alongside their handlers after the September 11 attacks. They were trained to locate people, but as the search continued, the prospect of finding survivors diminished.
Some dogs began to lose motivation. Their handlers responded with practice finds: a person could hide, allowing a dog to locate someone successfully and receive encouragement before returning to work. These were training exercises, not claims that actual survivors had been rescued.
The National September 11 Memorial & Museum describes these mock finds as one way handlers supported the animals through difficult work. Veterinary teams also helped care for dogs exposed to dust, debris and long shifts. The dogs were part of the rescue effort, and keeping them working meant looking after their physical needs and their drive to search.