A Jack Russell Terrier as a family watch dog? It depends what you are looking for in a watch dog. Do you want a dog that lets you know when something is not right by barking or growling, or do you want a family watch dog that would bite someone, maybe even you or your children.
Rottweilers and Dobermans may make good watch dogs, but I would not consider them a family watch dog. Especially if you have little children. It is not worth the risk of them hurting your child, or your childrens playmates.
All of the dogs that I have had in my life have been good family watch dogs. The main thing is to know your dog’s behaviors. How does your dog behave when there is somebody at the door that he doesn’t know? Does he growl or cower when scared. You don’t have to have an attack dog to have a good family watch dog. To me, a good family watch dog is one that will let you know by his actions when something isn’t right.
Your dog can sense things before you. Many dogs are also a better judge of humans than humans are. If your dog growls at a stranger, and that is not the dog’s usual behavior, that person may be showing signs of nervousness or aggressiveness that the dog senses, that you don’t.
So whether you want a Jack Russell Terrier as your family watch dog, or a mutt, as long as you get to know your dog’s behavior, he or she will serve you well.