
1) Working dog
Found on
https://www.crosswordclues.com/clue/guard-dog

A guard dog (also known as an attack dog or watch dog) is a dog used to guard against, and watch for, unwanted or unexpected people or animals. The dog is discriminating so that it does not annoy or attack familiar people. ==Barking== Both guard dogs and watchdogs bark loudly to alert their owners of an intruder`s presence and to scare away the i....
Found on
http://en.wikipedia.org/wiki/Guard_dog

Dog that stays with sheep without harming them and aggressively repels predators.
Found on
http://www.sheepusa.org/

a large, aggressive dog, as a German shepherd or Doberman pinscher, trained to guard persons or property and often to attack or restrain on command.
Found on
https://www.infoplease.com/dictionary/guard-dog
No exact match found.