ISLAMABAD: As Saqlain Arshad, 25, steps into a colorful kennel, Paal, a tracker dog at the Islamabad police’s Canine Unit, stands ready to join duty. This time, however, it is not an outside assignment but a mock training session that handlers regularly conduct to keep these dogs, whom their handlers proudly call “silent heroes,” in shape to take up field assignments. Arshad holds out a cap belonging to a colleague who hid a few hundred feet away. As soon as he loosens the leash, Paal leaps and pauses briefly to scent the cap before heading straight to the target crouched behind a car.