After you get all 5 dogs in some doghouse you will be able to use new dog treats for fetch some cool decorations and animals. You can do this in every harvestable Doghouse and you can to fetch with different number of treats - from 6 to 30. Less then maximum number of treats can get you Water Bowl, Dog Toy, Dogwood Tree (decoration) or in rare cases Toy Bone. Maximum number of treats will get you some animal as reward - Flying Squirrel, Brown Squirrel, Bat Cat, White Witch Cat, Grey Tabby, Fat Scarf Squirrel, Vineyard Cat