Sheltie to the Rescue: Volume 5 by Peter Clover
Emma is sure that going to Summerland Bay will be the best holiday ever, especially as Sheltie can go with her. But snobby Alice Parker is there and she is always making fun of Sheltie. When Alice and her pony get into trouble on a dangerous cliff path, Sheltie comes to the rescue and is the only one who can save them.