Lilly and the Octopus by Steven Rowley

 Steven Rowley picked Lilly, the runt of the litter, and this little dachshund became the center of his life for over a decade. The one day he noticed a growth on her head, which he named "the octopus" and focused all his efforts on defeating the octopus before it could take away his beloved dog. Part funny, part sad, and part downright surreal, the story shows just what a crucial role pets play in our lives. Aside from Lilly herself (whose thoughts we hear), my favorite character is the author's best friend, Trent, a fellow dog lover who is always there to offer support to Lilly's stressed-out and increasingly frantic owner. If you think this might be too sad to read, know that the story ends on an optimistic note.