police dog

名词 police dog:

1. any dog trained to assist police especially in tracking

1. All the time he was in the city the secret police dogged his steps.
   他在该市逗留期间一直受到秘密警察的跟踪。
2. Lead the way with the police dog; he'll soon smell the fellow out.
   带着警犬领路吧，它马上会把好家伙的行踪嗅出来。