Gr 4-6 When Zoe's mother moves to Los Angeles to pursue an acting career, the girl is shipped off to live with her grandmother, Dr. J. J. MacKenzie, a veterinarian who runs the Wild at Heart Animal Clinic. This fifth installment in the series finds Zoe struggling to deal with her mother's absence and learning to adjust to a new school. Her major project, however, involves her efforts to housebreak a new puppy, Sneakers, that just won't behave. Zoe learns through volunteer work at the veterinary clinic and advice from her cousin that sometimes the owner's lack of patience is the problem. Zoe also meets a therapy dog that was recently diagnosed with cancer. After working with Yum-Yum and his owner at the children's hospital, Zoe realizes how important the dog has become to the patients, and worries about how his death will affect them. Fans of animal-centered fiction will enjoy the undemanding story line and Zoe's dilemmas as she learns to fit in with the gang at Wild at Heart, train Sneakers, and prove to herself that she and her pet can make a difference in the lives of the hospitalized children. The author includes end matter about therapy pets. Jennifer Ralston, Harford County Public Library, Belcamp, MD