I saw this posted on the internet, perhaps it was even on this forum. If I understand it correctly, the kill bite is genetic, not trained. Please correct me if I misunderstood what was written:
"Re: prey drive vs. prey aggression
I think to try to define things in terms of "prey drive" vs "prey aggression" is overly simplifying things, and also erroneous.
Prey drive (and herding behavior for that matter) is rooted in the natural hunting sequence of canines:
find game (track) - stalk - flush - chase - catch - kill - possess (eat) OR retrieve (return to den)
Through selective breeding, humans have adjusted this natural hunting instinct to suit our purposes. Some breeds and individuals possess certain parts of the sequence, but not others. The most obvious examples of this are in the hunting breeds.
Setters and Pointers for the most part possess the early parts of the sequence: track - stalk - flush. But, because of selective breeding, it stops there. A bird dog who chases the game once flushed is going to get himself shot. Many hounds possess most, if not all, of the sequence. Including chase - catch -kill. The Beagle, for example, is a rabbit hunting dog. It chases the rabbits. If it could catch the rabbits it would, but it can't. The reason it is designed to be a small, stumpy legged dog is to make sure it can't catch the rabbits, or even get close, or else it will also be shot by the hunter. Other breeds have had most, if not all, of this hunting sequence bred out of them entirely.
Working and herding breeds like the GSD have also been bred to retain this hunting sequence, but in a slightly altered form that allows them to channel those behaviors into things like herding, protection, etc... rather than specific hunting behaviors.
Some don't have all of it, and these are the dogs who will chase, but don't try to catch or if they do catch they don't try to kill. Others will try to catch and kill. It doesn't depend on how strong the dog's "prey drive" is.. How vehemently it chases is a result of prey drive, but whether it tries to catch and what it does if it does catch isn't determined by it's level of drive, but rather what parts of the hunting sequence the dog came genetically programmed with.
Since catching and killing prey involves what could be considered an aggression component, whereas chasing alone does not, I suppose one could say that dogs who possess that part of the hunting sequence (and will catch and kill) have "prey aggression" in addition to just "prey drive". But as I said, I think that isn't exactly an accurate way to look at it."
I have four cats that I scraped off the streets and took in after Pit Bull maulings in various states of injury, degloving, dismemberment, etc. There was a fifth that did not make it. I can NEVER look at the breed of dog that did such heinous acts to such small, friendly loving companion animals and did it with such glee and enthusiasm with any semblance of anything good and cannot fathom the mindset that would. To me, there is nothing admirable about a breed responsible for the horrible slaughter of companion animals.