Exam I - Spirocerca lupi

Question 1

Spirocerca lupi belongs to which taxonomic class?

Answer 1

Class Nematoda

Question 2

What is the common name for Spirocerca lupi?

Answer 2

Esophageal worm

Question 3

Which animal would you expect to see in practice as a final host for Spirocerca lupi?

Answer 3

Probably a dog.

Final hosts include dogs, wolves, coyotes, foxes, hyenas, jaguars, lions, cheetahs, etc…

But don’t worry about all that crap… dogs.

Question 4

Name the intermediate host(s) for Spirocerca lupi

Answer 4

dung beetles

Question 5

Name the paratenic host(s) for Spirocerca lupi

Answer 5

chickens, birds, & lizards

Question 6

Spirocerca lupi adults can reach ___ cm in length

Answer 6

Spirocerca lupi adults can reach 8 cm in length

Question 7

Spirocerca lupi eggs usually measure about ____ µm.

Answer 7

Spirocerca lupi eggs usually measure about 30-35 µm.

Question 8

Is the Spirocerca lupi life cycle direct or indirect?

Answer 8

Indirect

Question 9

How long is the PPP for Spirocerca lupi?

Answer 9

~ 6 months

Question 10

Which stage of Spirocerca lupi is the infective stage?

Answer 10

L3

Question 11

Describe the life cycle of Spirocerca lupi

Answer 11

Indirect.

1. Egg with L₁ is passed in feces or vomit
2. Egg is ingested by intermediate host, where it hatches
3. L₁ develops to L₃(infective stage) and encysts
4. Paratenic host ingests intermediate host (dung beetle) or paratenic host & L₃ is liberated
5. L₃ penetrates stomach wall & migrates to thoracic aorta
6. Three months later L₃migrates to esophagus and provokes granulomas
7. (Another) 3 months later, adults develop

Simplified?

Egg + L₁ pooped out –> Egg eaten by beetle –> L₁ turns into L₃ –> Paratenic host eats beetle & liberates L₃ –> L₃ enters stomach & migrates to thoracic aorta –> L₃ moves to esophagus and f***s s**t up after 3 months of planning –> larvae grow up after another 3 months

Question 12

Where are you likely to find Spirocerca lupi adults in the final host?

Answer 12

Esophagus & stomach

Adults are embedded in granulomatus nodules in the wall of the esophagus & stomach

Question 13

What might you expect Spirocerca lupi larvae to cause in the aorta?

(besides a ruckus)

Answer 13

Spirocerca lupi larvae cause lesions in the wall of the aorta

Question 14

Describe some clinical signs associated with Spirocerca lupi.

Answer 14

Esophageal granulomas from adult nematodes can interfere with swallowing & cause vomiting, followed by weakness & emaciation

Question 15

What would be the most effective way(s) to diagnose Spirocerca lupi?

Answer 15

Endoscopy or radiography