Your child would trade every toy in the house for a real live puppy. It starts with a pack of silly dogs racing to a party and ends with a boy risking everything to save a mistreated beagle. The books grow from a toddler's first words to a story with real weight, exactly as fast as your child is ready for.
What climbs on this trail is how much the story asks of the heart, more than how hard it is to read. It opens in pure play: dogs being silly, a puppy dodging bedtime, a naughty dog running from a bath. Then it feeds the fact-hound in them, and hands them Dog Man for the sheer joy of it. The last two books are where it turns real, first a lonely girl and the mother who left her, then a boy protecting a dog from someone cruel. A dog-loving child will follow a dog anywhere, and this order just makes sure each place arrives when they're ready for it.