In all fairness, I don't speak Spanish, but the other comments here are breaking it down pretty clearly, that the officers spoke some really piss poor Spanish.
As far as police dogs, different dogs and even different dog breeds are trained exclusively for specific tasks...
- Violent Perpetrator Pursuit (Often German Shepard)
- On The Run Perpetrator (Often Bloodhound)
- Missing Person or Corpse Sniffing (Also Often Bloodhound)
- Drug Sniffing Dogs
- Bomb Sniffing Dogs
I'm no full expert on this, but I do know for a fact that they train different police dogs for specific tasks, and often (but not always) train specific exact breeds for specific tasks.
Still, dog in Spanish is perro, not that other word they said...