Canine coffee break?

Just as an introduction, I have a hardy interest in "dogs with jobs", like police dogs, seeing-eye dogs, ect.
Coming back from the mission trip to Eagle Pass on Saturday night we went through a usual Border Patrol checkpoint. Fortunately everyone had their IDs so no one got detained this time. :) The line at the checkpoint was longer than usual so we were looking around trying to figure out why. We saw one of the K9s and his human partner cross the (small) highway to go sniff the grass and do business for about 5 minutes. Then that pair came back to the checkpoint and the other pair went across the street to do the same thing. Was this the doggie-equivalent of a morning coffee break?