Our dogs are also also very good at picking up other cues. Not only can we not say "walk," but the "well..." as in, "well, time to take the dogs" gets the same reaction now.

Our SPCA-special (shepherd / husky / other?) learned after _one_ event that the tub running with the bathroom door open means that it's bath-time, and time to head out through the pet flap to the safety of the outdoors.