The Mystery of the Snow Puppy by Fran Manushkin

Katie's new puppy, Koko, has run away, and now the white doggie is lost! Pedro and Katie pair up to investigate. They are hot on Koko's trail, but some clues lead nowhere. Still the detectives won't give up. After all, solving this mystery is the only way to bring Koko home!
Binding: Paperback / softback