If you haven't read a Barbara Trapido book, you really should! This is a great one to start with, although it's out of order. That's of no great matter however! The beauty of her books is you can dip in and out of them in what ever order you like.
This hero is named Bob and it is a cat. Bob helped the drug-addicted street musician James Bowen back to live. Some years later James wrote down the story... | Photo from book title with Pin-It-Button on http://www.amazon.de/dp/1444737112/ref=cm_sw_r_pi_dp_3xwwsb03T9RQK