ADN recently had a good article about search dogs training for missions:
Lost? In trouble? These Alaska dogs will sniff you out Creating a mission-ready dog/handler team doesn't happen by accident. It takes about two years, start to finish, to certify in any of the search disciplines represented by teams of Alaska Search And Rescue Dogs: Wilderness, avalanche, tracking/trailing, cadaver and urban disaster. Handler and dog can expect to train specific search skills two to three times a week in addition to general bonding time and learning an array of obedience skills through voice and hand signals. Each team re-certifies in its given disciplines every two years.
It's that bonding time and deliberate practice in unusual environments a few times a year that helps Alaska Search and Rescue Dogs handle with aplomb circumstances that a typical family pet would never tolerate. They sit in loud, noisy helicopters and ride slung across their handler's shoulders during ski trips. "They know 'Dad's gonna take care of me here.' You can tell them to do just about anything, and they're going to do it," explained Brusseau.
I've worked with ASARD handlers and dogs on missions. They are awesome. In most search situations, the first thing the Incident Command team will request is dogs. They aren't infallible, but in many cases they are hugely effective in searches.
Back in late September I played search subject for a dog in a short exercise. It was really cool. From my hiding spot I could see the dog zig zagging across the terrain. When the dog got downwind of me and caught my scent, it suddenly turned and came like a laser to my position! Very cool!
If you or a loved one is ever the subject of a search, you are lucky if the SAR team has trained dogs available.