It’s in the bloodlines
Professional, reputable trainers tend to specialize in protection dogs. In other words, a trainer might focus on bloodlines that have proven success as working dogs.
On the other hand, a breeder might select bloodlines that boast successful show dogs, while neglecting aspects like working ability.
Then there are backyard breeders. These are usually breeders simply breeding two dogs together, usually without screening for health or temperament.
Aside from the many potential genetic defects that backyard breeders don’t consider, these dogs can be more unpredictable. Therefore, it’s a dangerous gamble looking for a guard dog here.
Not every pup has what it takes to be a guard dog, either. Even from reputable breeders.
Remember, some breeders select bloodlines that produce successful show dogs. These dogs are generally healthy, purebred animals with minimal chance of suffering hidden defects.
The best protection dogs are screened as puppies even with the right breeding. They can go through months, if not years, of training to become reliable protection dogs.
Will a normal family pet dog protect you from an intruder?
It is unlikely that a family dog that has not been trained specifically in guard work will protect you from an intruder. They will bark, growl, or may even have their fur raised, but biting is unlikely.
This, however, is again dependent upon breed and bloodline. A German Shepherd or Doberman Pinscher has a higher chance of defending against a break-in or a mugger on your walk.
If you have a Havanese though, don’t expect them to jump in and save the day!
If you have a Border Collie, you may want to read Border Collie Resource Guarding: (Possessive Growling)
What will my dog do if Im attacked?
What to do if your dog is attacked by another dog