Since Buster is a rescue, I would highly suggest that you have DNA Fanconi testing done. It is a cheek swab that you do yourself. You can order the test at www.offa.org for 65.00. Money well spent for peace of mind and know your Basenji's status. Scroll down till you get to Fanconi DNA
Welcome to the Forum. It sounds as though this 'protectiveness' has been going on a long time. I agree that probably it would be best to get help from a behaviorist but make sure that they have experience of Basenjis. In the meantime keep him away from your guests. It's possible that he's stirred up by the excitement so it's best to try to keep him calm when people are around.
and I am so proud of my greatgrandchilden, as my brindle US import, Akuaba?s Original Sin, aka Oliver, sired the first litter of brindles in the Czech republic - Oliver has his own website if you care to see him - he was a lovely boy - www.fallohide.dk/akuabas_original_sin.htm
Hi, I know Oliver from photos, he was a very beautiful brindle male :p.