Guard traoing dogs are hand seleceted, right from the parets temperment. they have to undsergo obeservational tests such as testing if the dog has strong or weak nerves. A dog with weak nerves can end up biting the handler or the decoy in the wrong areas.
Then when the pup is young, the prey drive must be increased by certain excercises and obediance commands, when the doh\g is nearly mature at about 1.4 months then gurd dog trainig is given. Pls do not fall for trainers who will say yes that they ican make a guard dog out of your pet. It is imperative that the dog is taught the release command. because if your dog attacks on command it should do the "out" on your command also.