This book emphasizes the need for responsible pet care and handling. It emphasizes that all pets, even small ones, are not toys and that they can be hurt inadvertently if you're not careful. The supplies needed to care for a leopard gecko are outlined carefully, and gecko facts are woven into the story of two children whose family buys a gecko. The fact that "Spotty" is a family responsibility--not simply that of the children--is communicated.
However, humane families are likely to wince at the fact that the family purchased the lizard at a pet shop, and the fact that they decide to breed their pet. I am also not a fan of people referring to their pets as "it"--this is done throughout the book, even after the family establishes that Spotty is male.