My first B started challenging at 16 months, we neutered him shortly after and it did seem to help a little. However it was only a small part of the solution not the whole solution. The closest thing to a magic solution is the excercise and mental stimulation. Basenjis are one of the most intelligent dogs and need more excercise and stimulation than most. I have generally found males to be much easier to work with and less aggressive than females. Correct discipline, structure, positive reinforcement, patience / stubbornness and enough excercise are the keys. Usually when people have problems with their dogs it is the humans which are the cause, not the dogs.