Hint: Pet store
The answer to this puzzle is:
1. BULLDOG
2. FOOD
3. BEDDING
4. COLLIE
5. CAT
6. CLAW
7. GERBIL
8. DOG
9. CAGE
10. HAIRBALL
11. SNAKE
12. TAIL
13. COLLAR
2. FOOD
3. BEDDING
4. COLLIE
5. CAT
6. CLAW
7. GERBIL
8. DOG
9. CAGE
10. HAIRBALL
11. SNAKE
12. TAIL
13. COLLAR