1) Alert guardian 2) BBC Television programme 3) British television spin-off 4) Burglar alarm alternative 5) Canine guard 6) Cerberus 7) Controller 8) Defender 9) Defense against intruders 10) Doberman or Rottweiler 11) Furry guard 12) Guard of a sort 13) Guardian 14) Manager 15) Protective pooch 16) Protector 1) Biter 2) Housedog 3) Keeper 4) Kuvasz 5) Mastiff 6) Pinscher 7) Schipperke 8) Sentinel 9) Snarler 
• (n.) A dog kept to watch and guard premises or property, and to give notice of the approach of intruders.
[Noun] An organisation or person who tries to stop undesirable practices such as waste, poor taste or inefficiency.
A person or organisation that monitors the practices of companies to ensure they are nor acting illegally
Watch'dog` (wŏch'dŏg`) noun A dog kept to watch and guard premises or property, and to give notice of the approach of intruders. 
[n] - a dog trained to guard property
guard dog noun a dog trained to guard property