I don't care for dogs, but I don't fear them either. It's true though that even the most "aggressive" breeds will only be that way if they're not trained otherwise. It can be that same for cats, as hard as they are to train, but cats are less likely to be on the news for taking a chunk of out someone's leg even though they can cause some serious damage.
Any serious pet owner, and I include Tooner in this, will know to train them properly, but if they feel there might be an issue will take appropriate action to confine or minimize the risk. You don't have to put a dog in another room before opening the front door, just make sure you block their path so they don't run out when you open it.
Just because the pet you own has never attacked you, doesn't mean they won't attack a stranger at your door and far too many people don't understand that.
I love animals myself, but I understand much like people your pets have their own personalities and they don't always react well to someone new showing up.