She's famed for being the Material Girl, but Madonna's (search) next illustrated children's book is about how wealth is overrated.

"Lotsa de Casha" (search) will be released next summer, the singer's publisher, Nicholas Callaway, said Wednesday.

"All the characters in the book will be animals, and Lotsa de Casha is an Italian greyhound who has all the money in the world but no happiness," said Callaway. "He thinks only of himself."

"Lotsa de Casha" will be the final installment in Madonna's five-book children's series for Callaway Editions.

She's now promoting her fourth book, "The Adventures of Abdi."

Madonna's other books are "The English Roses," "Mr. Peabody's Apples" and "Yakov and the Seven Thieves."