Aww! Levi and I went to our Donate Life walk a couple of weeks ago. He had a great time, but he is super-social. My best friend's dog, however, hates to be in public and hates to walk...so he rode in a backpack the whole way. Could you bring a carrier of some sort in case Kaji gets scared? That way he can walk if he feels up to it, or ride along if he needs to feel more secure.
I attached some pictures from out Donate Life walk. Maybe that will convince you to take Kaji!