Doggie boots were donated, but the dogs loose all tactile sense when their feet are completely covered. At the Trade Center, we wrapped gauze in rolls at the back of the foot where the major tendons and blood vessels were, and then wrapped the foot with Vet Wrap or CoBan and left the toes exposed so the dogs could "feel".
This is me and Bella at the WTC, and you can see the wrap on her feet.
Chris used his ASP to break a hole in the roof to allow more scent to escape, and the dog "alerts" when it detects human scent. A dog that does both live-find and cadaver work will alert differently for live vs. cadaver.
Unfortunately, no live finds were made, and remains or areas where scent was found was marked for other teams to search by hand. Cadaver scent was found in this pile and was marked "MC-K9" and the crews coming in would search the debris by hand. Might find a person, or could be just a finger. You never know until you look.
There was car at the Trade Center that was smashed about twenty inches flat, and Zeke was all over it. There was cadaver scent, but how do you recover something from that? We found shirts buttoned up with no one in them from the forces of the floors pancaking as they collapsed.
We usually go every year to the WTC memorial at Ground Zero, but this 9/11 we were searching again and adding more emotional baggage to an already mentally overloaded calendar date...