When twofight, the looser almost never dies. He simply surrenders with ritual gestures (lying upside down, offering the throat to the winner). This attitude inhibits, automatically, the stronger puppy's aggressiveness, who immediately stops attacking. Therefore, victories have mainly a symbolic value.Unfortunately, man has perverted this behavior, by means of selection, and training some of them for fighting. As a result, some are capable of fighting till death with their siblimgs. This is a perverted behavior that is currently much in use. But nature has an even stronger power than men, therefore, any fighting dog's breed, if evolved freely will go back to rituals within few generations. Even more, all combative animals, selected and trained, can be retrained by an expert. Dogs, definitely, are not ferocious or bloodthirsty by birth, regarding their brothers, but can be trained for that by men. There are not enough words to describe these people, and those coming to my mind I rather prefer not to use them. The inter specific behavior is very different, cause in this case nature allows to attack and kill. Obviously, the pack kills when they find a prey (killing to eat is legal, in a natural context). And as "prey" is considered everything with small size and running, very often run after cats or kids.
The pack can kill when against a predator, for instance, a puma. In this case will also be a fight to the death, because predators are a menace to the pack, and cannot be allowed to stay within the group. Nature has nothing against the predator being killed, that usually happens (unless he can escape), and then no kind of inhibition takes place among(or wolves). So, definitely, fighting within the same specie rarely ends in death of one of the contenders, and are ruled, specially, by ritual gestures.
Fighting between different species, on the contrary, tend to end with the death of one of them, and lack any ritual component. The question, is then, if forhumans are congeners. The most immediate answer will be negative, cause obviously we are a different breed. However, the correct answer is yes, or better say, that's how he sees us. In fact, this is the imprinting main target. As the puppy, like a kid, starts his psychological development from the very moment of birth, we will now follow him from his "zero hour", that is from his birth till the moment he discovers us.