Jealousy surrounds the arrival of a new baby, in this case a puppy, in this latest of sweet-tempered books from about a golden retriever (Boomer Goes to School, 1996, etc.). Boomer notices a small bundle in the kitchen; soon a black nose and pink tongue appear in the form of Baby Boomer. Baby is instantly the center of attention. His back is lovingly scratched and his belly rubbed, while Boomer feels ignored. Among all the new toys, Baby plays with Boomer's own favoritehis old green tennis ball. Using unembellished language and plain sentence structure, the narrator reports Boomer's feelings, ``Later, everyone went outside to play. Boomer was very excited . . . He waited and waited for someone to throw him the ball. But no one did.'' Baby wins Boomer over with a wag of the tail and a lick of the nose, enlisting the older dog in play. The crowning moment is a spread showing Boomer as onlooker to the new puppy's masterpiece--a paw-printed living room with a chewed-up shoe, knocked-over plant, and spilling goldfish bowl. The affectionate watercolors will find their audience in dog lovers and children with new siblings alike. (Picture book. 2-6) -- Copyright ©1999, Kirkus Associates, LP. All rights reserved