Sgt. Randy Nichols, the officer holding onto your leash opens the back door and lets you into the squad car.
"Hey Butch? You ready to go sniffin' for drugs at the airport?" He says encouragingly.
You give a big excited Woof! Somehow, pleasing Randy makes you happy. He could have said, "Hey Butch, wanna go to the vet?" and you still would have been just as excited.
The squad car takes off down the road and you're ready for your first assignment... thing is, you don't really know what drugs smell like.