Exam II - Oesophagostomum spp

Question 1

What is the common name for Oesophagostomum spp?

Answer 1

Nodular worm, pimply worm

Question 2

What is/are the host(s) for Oesophagostomum spp?

Answer 2

Cattle, sheep, goats

Question 3

Describe the appearance of Oesophagostomum spp

Answer 3

Adults are 2.5 cm, white. The anterior end with a large cephalic vesicle (see arrow in photo below)

L₄ are less than 0.5 cm nodules found in small & large intestinal walls (more often in large intestinal walls)

Eggs are typical strongyloid, up to 85 um, thin shelled, outser surface of shell smooth, containing a morula

Question 4

Describe the life cycle for Oesophagostomum spp

Answer 4

Direct. Typical strongyloid life cycle. Eggs hatch in feces and develop to L₃. When ingested they enter the wall of small & large intestine and L₄ develops in nodules. Many of L₄ will stay arrested for up to a year.

When L₄ emerge they develop to the adult stages, the males and females mate and females lay eggs.

PPP is ~45 days

Question 5

What is the site of infection for Oesophagostomum spp adults? L₄?

Answer 5

Adults in lumen of large intestine.

L₄ in wall of small or large intestine

Question 6

What is the PPP for Oesophagostomum spp?

Answer 6

~45 days or longer

Question 7

Describe the pathogenesis & clinical signs associated with Oesophagostomum spp

Answer 7

Anorexia is most important. It is caused by intestinal discomfort, starting with larval migration to gut lumen and persisting until death or recovery

Acute disease is rarely seen.

Chronic disease due to presence of larval stages and adults. Diarrhea can be severe.

Question 8

What would you be looking for in a fecal examination of Oesophagostomum spp?

Answer 8

strongyloid L₃

Won’t be seen in acute disease since not yet patent, but will be present in chronic disease

Question 9

Treatment & Prevention options for Oesophagostomum spp?

Answer 9

Anthelminthics, management. Animals usuall do not develop good immunity to infection