Never seen dogs going thru the cabins on a regular basis. More often in the holds and baggage carts after unloading. The quantities that they are concerned about wouldn't fit down your pants. Individual amateur smugglers are usually found out by customs agents interview and facial tell tales. Interesting that some of the dogs used are looking for agricultural products of another kind that could affect American farming. Don't try to hide a sausage fruit or cheeses. Some dogs are trained to smell currency. Most dogs when sensing their particular product will simply sit beside you. He ain't being friendly.