Use these level password:
2: Dice, Bone, Bone, Dice
3: Dice, Key, Bone, Machine
4: Dice, Bone, Food Bowl, Toy
5: Bone, Dice, Dog, Bone
6: Bone, Dice, Machine, Food Bowl
7: Bone, Bone, Paw, Dog
8: Bone, Bone, Paw, Toy
9: Bone, Toy, Key, Bone
10: Bone, Toy, Key, Dice
11: Bone, Toy, Bone, Machine
12: Bone, Machine, Dice, Toy
13: Bone, Machine, Toy, Key
14: Bone, Toy, Paw, Food Bowl
15: Bone, Toy, Toy, Machine
16: Bone, Paw, Toy, Toy
17: Toy, Bone, Key, Bone
Bonus 1: Machine, Dice, Dice, Dice
Bonus 2: Machine, Dice, Dice, Machine