Different Types of Search Dogs
Tracking/trailing dogs are trained to find a specific scent and follow it to the victim. A scent article is usually used in training and preferred in actual searches to give the dog a "clue" of the scent to find. Tracking/trailing dogs can be trained on-lead or off-lead, depending on the dog and/or the handler.
Air Scent Dogs
Air scent dogs are trained to focus their efforts on specific areas. These dogs follow scent in the air and typically work off-lead. A scent article can be used, although these dogs have the ability to locate any human in the defined search area.
Cadaver dogs are trained to locate human remains. The remains may be buried or hidden, and may be dismembered. Various material is used to expose the dogs to this particular scent.
Victims that are caught in an avalanche, or even fall into a snow cave or tree well, are nearly impossible to find by the naked eye. Avalanche dogs are trained to detect human scent rising up from the snow and dig until they find the victim. Avalanche dogs cover more ground in less time than several human searchers can cover, which explains their importance.
Water dogs are trained to pick up scent in the water and alert their handler when they find that scent. Similar to picking up scent in snow, the scent rises up to the surface in the water. Cadaver dogs, also trained as water dogs, can be useful in drowning situations