very aggressive St. Bernard

Question
I have a male St. Bernard who will be 2 in December. He was neutered over
a year ago. His aggressive behavior has been an ongoing issue for about a
year now. I can't take him anywhere to be seen at this point because of his
cujo abilities. That is about the only way I can put it. He has already bitten
and drew blood on 3 individuals. The fourth is my 11 year old who had to get
stitches last week for this. I love my saint. But I am at wits end with the
behavior issue. Noone can come to the house without being attacked. He is
not attacking on all four paws meaning he is on his hind legs and attacking
that way. He is a very large dog. He weighs over 200 lbs and standing on his
hind legs he is at least over 5'4".  That is my height and he is taller than I. I
am scared for my kids and getting in trouble with the law if someone presses
charges. Apparently the breed I have is an extra large saint who is dry
mouthed. Could there be a brain tumor going on or some other health issue I
should be looking out for? I was told that if the whites of his eyes turn red as
he is in attack mode that a brain tumor could be possible. His whites of his
eyes do turn so dark that they almost look black. Please, I need help and am
willing to do what ever it takes to fix this problem. Like I said, I LOVE my
saint, but I am scared of what could happen. Help me please.

Answer
My heart goes out to you.  I've seen a few human aggressive Saints.  It is an ENORMOUS ABERRATION in the breed and cannot be tolerated.  Perhaps your dog has an endocrinological issue or a neurological flaw (such as pituitary tumor, etc.), but the only way to know this is cranial MRI and CT scan, both very expensive tests and you would need to travel to a teaching hospital (veterinary college).  Even then, successful treatment of such a problem would be prohibitively expensive.  Your dog clearly has some sort of physiological problem, given your description of the whites of his eyes.  Even bringing in a certified applied animal behaviorist will not help if the dog is neurologically impaired or suffering from an endocrinological imbalance.  Find a veterinary neurologist (if you can) and have the dog fully evaluated.  What I have to say next, you will not like.

A dog this size who is actively human aggressive is a clear and present danger to everyone.  You could lose a child; your dog could severely injure an innocent human (neighbor, visitor, other family member); you could be sued and lose your house.  He has totally lost bite inhibition and broken skin on three people (as you report)and this last attack is on your own son.  Even if the dog has a physiological abnormality and medical condition, he's learned far too much about active aggression and his size makes him a serious threat.  Also, the dog is suffering enormously.  Whatever is prompting his behavior is confusing him, frightening him, and may even be painful (dogs do not demonstrate pain as we would expect, it's often quite difficult to know they are experiencing it.)  He's suffering; your family is at risk.  The most humane thing to do, and the safest, is to euthanize this dog.  When seeing the veterinary neurologist (if you are able to find one), discuss this option.  A strong sedative should be fed to the dog at home (in a hamburger or other goodie), the dog should then be taken to the vet clinic and sedated with a syringe, and when he is not conscious of what is going on, he should be put down.  You can't take a chance with a dog this size.  In my files, I have pictures of children (from several bite litigation cases) who have been killed by the "family dog."  You don't want this experience.