>> “The only, absolute and best friend a man has, in this selfish world, the only one that will not betray or deny him, is his dog.”
Well, this is far from absolute, isn't it? :) There's a fair number of vicious attacks of a dog on his owner. Oftentimes pitbulls (are they even dogs or rather "creatures"?!), but other breeds do it too. So ... nothing is absolute :P
Mostly, if not entirely due to intentionally poor breeding practices. Who betrayed who?
The quote doesn't insist all dogs are infinitely loyal.
Your disgusting prejudice aside, I've never met a pitbull in public that wasn't sweet and loving - which reinforces my suspicion that the real problem with them is the sort of psychotic, uncaring owner they attract.
When I was young, it was Dobermans that were demonized, and likewise the dog of choice for assholes who abused them as mere security devices.
For another example of betrayal, one of the cronies in Katherine the Great's court always gave a dog to his girlfriends whenever he started a new relationship. Then if the dog ever greeted some other guy familiarly, he inferred he was falling out of favor. He probably learned that trick when someone did it to him, because he would let the other guy know how he was rumbled before graciously bowing out.