Many hunting dogs have taken on multiple roles in the lives of their owners and one of the more important roles is that of guardian. The natural hunting instinct transfers quite well into the realm of the watchdog and German Shorthaired Pointers are no different. It also helps that the hunting dog is bred to work closely and develop a tight, long-lasting bond with his owner and family. This spurs the dog to instinctly protect his humans, though thankfully most hunting dogs do not (or at least should not) display direct, active aggression towards humans. Another point in favor of the hunting dog is its intelligence; with a little skillful training, these dogs can be taught how to be effective watchdogs rather than barking unnecessarily all day at the slightest of sounds. Hunting dogs like GSPs have numerous characteristics that allow them to be effective guardians; GSPs are especially gifted because they are such versatile hunting dogs, encompassing a wide variety of canine virtues.
The German Shorthaired Pointer is an intelligent and extremely affectionate dog that can be easily trained and that is highly cooperative. He is also incredibly bold. His affection towards his family and his boldness equip him with the capability of making a good watchdog, as he is brave enough to stand guard over the family that he loves. He is also very highly trainable and so can be taught specific commands to enhance his watchdog duties. Though they are highly affectionate, they tend to be slightly wary of strangers until their family accepts them; until this point, they will sound the alarm whenever somebody new approaches their territory or their family.
They are extremely alert dogs, having to keep track of downed game to be able to retrieve it, and so they are tuned in to everything that's going on in their surroundings. Since they are so intelligent and so willing to please, they can also be trained to discern who is wanted and who is unwanted, barking an alarm only when seeing someone in the latter category. They are extremely loyal dogs, having been bred to work closely with hunters, though they are trusted enough to work on their own. They can also be trusted as guardians. Their natural guarding instinct could become somewhat problematic if not trained properly; indeed, this is not a breed for the inexperienced owner. If firm, consistent obedience training is not undertaken at an early age, the German Shorthaired Pointer could simply become an incessant barker, alerting you to the arrival of the ice cream truck, rather than carry out useful watchdog duties. Furthermore, if not taught to not view all strangers as a constant threat, the German Shorthaired Pointer may become unpleasant to be around and may actually develop aggressive behaviors towards others outside his family.