//I myself have wondered this. My Great Dane Lena was very dog aggressive. I could not for the life of me figure out how I could have caused it. I am not afraid of dogs, nor do I find them a threat in any way. I am glad that I am not the only one who has had to work with one of these issues in the face of being told that it was "my issue". // I believe you, allllllllll my other dogs were fine. What, suddenly, *i* displayed issues when i got this one dog? Sometimes, in a multi-dog household, 3 of the dogs are just fine, but ONE dog is dog-aggressive, what, only that one dog can detect "their owner has issues", but, the other 3 dogs are too dumb to notice all the owner's issues? rofl. I myself think dog-aggression comes in more than one form, there is the induced kind, like Michael Vick's dogs who were trained to be dog-aggresive, but were probably born 'normal'. 95% of Vick's dogs were rehabilitated back to normal dogs, they were probably born normal, the dog-aggression was INDUCED upon these normal dogs. BUT i do believe, some dogs are BORN that way. I know, i know, evvvvvvveryone will disagree, we've all been taught/hypnotized, that dogs are all born perfect, THAT ALL DOGS ARE BORN WITH NO ISSUES already there, IMPOSSIBLE any issues could be in their brain's wiring. and any issue they have is result of human issues/mishandling/improper socialization/abuse/something!! We do not even question it, everyone "knows" this!!! It is "a fact" that all dogs with issues have been mishandled in some way....riiiight. But, i myself, believe dogs are born with one of three personality types/brain designs/whatever. #1) The 'normal' dog #2) The shy dog #3) The dog-aggressive dog. that is my theory. Shy dogs, can be noticed at birth. IN the litter box, they can say, "This puppy here, ducks down, is very shy, creeps away." and that puppy, will always be shy. If you were to meet that dog, at age 1 or 2, without knowing a thing, you'd think, "This dog has been abused." but it wasn't. It was BORN that way. Shy dogs can be made somewhat better or worse, depending on how they are handled, but, they will always be shy. The dog-aggressive dog, is easily spotted to be dog-aggressive by an alert owner, by about 4 to 6 months old, and it is undeniable by age 9 months old. *IF* it shows up prior to that, it is either missed, put off to "a bad day", immaturity, play, lack of social skills, babyhood, or just not noticed--puppies being aggressive is even kinda cute. By age one, the owner of this dog is usually seeking help. People call to them, "Hey, you need Dog Whisperer!!" and the baffled ppl wonder what "they" did wrong to have a dog-aggressive dog, when all their other decades of dogs were all just fine!!! and since we are all told, if your dog is dog-agressive = it is our fault. THE NUMBER ONE REASON DOGS IN USA ARE PUT TO DEATH is dog-aggression, and/or people aggression. This far outnumbers even being put down for cancer or illness. It is THAT hard to cure, cuz it is wired into those particular dogs brains, imo. I currently do believe people-agression is taught/ learned, a result of not being socialized, something, so far as i know right now, and ppl agression IS VERY highly curable. My own dog was also ppl=agressive, but, we cured him of that 100%. With this type of inborn dog-aggressive dog, it does not much matter how well you socialize it, how you handle it, it WILL be dog-aggressive. LIke type I diabetes, you can control it but not cure it. Like the dog behaviorist who wrote "Click to Calm", she did everything right, yet, her pup turned up to be dog-aggressive. Like the shy dog, you can make this dog somewhat better or worse, but, it will be an ongoing issue for dog's whole life. anyway, that is my two cents. I do not expect ANYONE to agree, especially not anyone who never actually lived with a dog-agressive dog, --------->but please be adult, and attack my idea, but not me as a person.