You raised some valid points in regard to breeders mating dogs for there conformation and no regard for demeanour . This is common with show breeders . Greyhound people won't mate aggressive dogs as they can't be raced so no point continuing the line. I have used basenji,s for the past thirty years and all were intact dogs run with another dog of a different breed and none were aggressive to other dogs . I could not take a dog out if it was aggressive as most other hunters use a dog of a large size that would put a basenji in its place if it was aggressive . I repeat in saying it is the owner who must lead from day one as basenji,s will try to be boss if you let them. By accident I leant what to do to train a basenji . My boy walks off lead sits ,stays comes when called , just as any dog can do but again it is up to the family to put the time in . All I know is my method has worked for me . Once a basenji has been allowed to develope a bad habit it is very hard to break so only let them develope goods ones from the start and you are half way there. Never ever let a basenji be boss . Aggression should never be allowed and if the early work is done they will never show any . No need. If the dog starts to get aggressive let it know your feelings through your voice and physical presence and never back down . They read us like a book so you have to write it.

I don't want to sound personnel but if you are in control why does he keep showing aggression to other intact dogs. By taking him away from the other dog is not teaching him not to be aggressive . He may see you as boss but he wants to be second in charge and see,s all other intact dogs as a threat to his position. Don't be to proud to use a muzzle , and as I said take out to mix with intact dogs . As he can't hurt them and will soon relize,s this you need to stand up and let him know your displeasure using voice and physical presence and a small water pistol as he will hate being squirted. You should find the water pistol works a treat. I would do this every few days until his stops the aggressive behaviour , then I would try without the muzzle but always keep the water pistol with you and let him see it as he will remember what happens when he acts up. This is a method I have used to help mates control their pig dogs . I am by far an expert and are always prepared to Liston to others thoughts as this is how I learn.