In light of the paralysis of her right front leg, walks with Bella are now sharply-limited in scope.
In light of the failure of Friday night's wheelbarrow experiment, on Saturday, I purchased a hand truck that converts into a cart, in order to give Bella the option the option of riding rather than hobbling through vacant stretches of pavement. So far, Bella seems to grasp the concept, although she hasn't yet learned to jump up on the cart when she is tired. We haven't run into many homeless people yet, but so far their reaction seems to be, "hey, nice cart." Oh, and "poor dog."
So, walks with Bella continue, for now.