The major theme of all the Dolittle books is the concern for life and living creatures, especially animals. Dolittle is a doctor, concerned about health and life. Though he treats animals, he is also kind to people and during the course of his adventures rescues a number of them. In contrast to the Colonel, who treats Tommy rudely because he is a child and a member of the working class, Dolittle treats Tommy "as a grown-up friend" and enjoys his visit with Tommy's parents. Dolittle's concern for the hermit Luke leads him to translate dog language at Luke's trial in order to save him. To save the Long Arrow and his co-workers buried in a cave on Spidermonkey Island, Dolittle enlists the help of the Jabrizi bug and works until the natives are freed.

Allied with Dolittle's concern for human life is his hatred...