Everyone thinks that dogs worship their owners and see them as gods of some sort. This may be true in most cases, but it is not always the case. As a veterinarian, I have studied animal and human / dog behavior and their relationship for 30 years, I can confirm that sometimes, no matter what you do, the dog and its owner will never adapt.
Tech Racus, a whiten dog with a sharp print. He very much hates his new owner Rick, not friendly but mysterious with Rick's wife, Cindy. Although Rick was a wonderful man by humanitarian standards, Roccus caused him unbearable inconvenience, and he did the same with his former owner. He slowly began to identify and guard the place. Eventually he became so bad that Rick had to call on his way home to ask Cindy to restrict Rakos for fear of being attacked.
For Ricos, Rick was an unwanted person in his home. It all ended badly one day when the Rooks were tied outside outside while Rick was cutting the grass. Eventually Roccus managed to escape the restriction, then flew towards Rick, and his teeth exposed to intent to commit serious bodily harm. A wrestling match took place; the police were called in and the animal was taken control while Rick was waiting with Ruckus surrounded. You won't really want to know how this story ended: I'm afraid it didn't go well for Rakus.
While there are dogs like Roccus that obviously do not like their owners, others do not have the pleasure of living under the same roof with them. They barely tolerate certain people because they have no other choice. After adoption, these hopeless dogs find themselves forced to accept owners who do not interest them. Some of them withdraw and remain terrified always. Others simply accept this treatment as normal and continue to live as much as they can.
In some cases, dogs have a good reason not to love their owners: poor treatment weakens and severely damages the animal's relationship with humans. For example, a brittany hunting dog was constantly stunned while training with an electric collar. One day the dog hid from it and remained lying under the bed. When the man tried to drag him from under the bed the dog bitten him. You can say that the man got what he deserved. The behavior exhibited by the dog was hostile and frightened directed towards the owner.
Curiously, this direct link between mistreatment by the owner and what happened will not explain Rox's position with Rick, who never treated him badly. It seems that Rocks is likely to have been severely abused by a man at a critical stage in his life, especially in the first three to four months of his life and has never been forgotten (almost like PTSD).
The German Shepherd dog, which I wrote in my book, "The Dog I Love Much," was afraid and not hostile to its owner. In this case, like the Rocks position, what he paid for human hatred was not what the owner did but what other men had done previously with the dog.
But the dog's reaction was not as protective or hostile as the Rocks. Instead it was pure fear without hostility, probably because of his inhibitory mood. When the man returns home, the dog runs and hides and does not reappear until the man leaves. The dog never interacted with him except in distant situations.
When a diabetic man's wife faints sugar at night (a very dangerous situation), the dog runs to the man's side of the bed and tightens the bed cover until the man wakes up and realizes the problem. A dog's love for a man's wife helped him overcome his fear and asked for help when she needed it. Courage is not about fearlessness, but about having the will to overcome it. By this measure, the dog was brave, although he still preferred the male owner had never been found.
So when you hear the words "best friend of man" about dogs and they "love unconditional love", they are only true if a person adopts a compatible pet and invest time and effort to show understanding and appreciation for the dog. Long walks, lots of fun, regular meals, clear communication, good driving and passion will create the dream dog everyone wants.
This is another example of what the Beatles said in one of their songs: "The love you give is equal to what you take." Bad owners or those who are used to punitive training do not enjoy the amazing bond they could have with their dogs, and their dogs don't like them either.