I believe that it is not a bad idea to have a dog in your private house, but the dog is not for defending your house only. It is also your friend. Besides, it is not so efficient as a piece of specialized equipment. So, I believe that dogs are good, but it is also better to set up a specialized security system. Only then you could be sure that you and your house are safe. I can suggest you look at this system https://ajax.systems//. It is quite popular on the market and I'm also using it myself.