1. Adult nematodes found in the Heart (right atrium) of dogs ........ Dirofilaria immitis
2. Adult nematodes NOT found in the Heart of dogs .......... Go to: 3 & 4

3. Adult nematodes found in a Subcutaneous nodule in the legs of dogs ........ Dracunculus insignis
4. Adult nematodes NOT found a Subcutaneous nodule in the legs of dogs .......... Go to: 5 & 6

5. Adult nematodes found in the Kidney of dogs ........ Dioctophyme renale
6. Adult nematodes NOT found in the Kidney of dogs ........ Go to: 7 & 8

7. Adult nematodes found in the Abdominal cavity of dogs ........ Dioctophyme renale
8. Adult nematodes NOT found in the Abdominal cavity of dogs ........ Go to: 9 & 10

9. Adult nematodes found in the Cecum and Large Intestine of dogs ........ Trichuris vulpis
10. Adult nematodes NOT found in the Cecum and Large Intestine of dogs ........ Go to: 11 & 12

11. Adult nematodes found in the Small Intestine of dogs ........ Go to: 13 & 14
12. Adult nematodes NOT found in the Small Intestine of dogs ........ Go to: 21 & 22

13. Adult nematodes are thin and less than 1.0 inch (2.5 cm) long ........ Go to: 15 & 16
14. Adult nematodes thick and more than 1.0 inch (2.5 cm) long ........ Go to: 19 & 20

15. Adult nematodes possess a large buccal cavity ........ Go to: 17 & 18
16. Adult nematodes do NOT possess a large buccal cavity ........ Strongyloides stercoralis

17. The buccal cavity is armed with hooked teeth (or fangs) ........ Ancylostoma sp.
18. The buccal cavity is armed with round cutting plates ........ Uncinaria sp.

19. The tail of the male worm is finger-like ........ Toxocara canis
20. The tail of the male worm is triangular and NOT finger-like .......... Toxascaris leonina

21. Adult nematodes found in the Stomach of dogs ........ Go to: 23 & 24
22. Adult nematodes found in the Vomitus of dogs ........ Go to: 23 & 24

23. Anterior end is bunt with a cuticular collar ........ Physaloptera sp.
24. Anterior end is pointed with large lips and cervical alae ........ Go to: 25 & 25

25. The tail of the male worm is finger-like ........ Toxocara canis
26. The tail of the male worm is triangular and NOT finger-like .......... Toxascaris leonina