Exam II - Ostertagia ostertagi

Question 1

What is the common name for Ostertagia ostertagi?

Answer 1

Brown Stomach Worm

Question 2

What is/are the host(s) for Ostertagia ostertagi?

Answer 2

Cattle

Question 3

To which taxonomic family does Ostertagia ostertagi belong?

Answer 3

Trichostrongylidae

Question 4

To which taxonomic class do Ostertagia ostertagi belong?

Answer 4

Nematoda

Question 5

What is the PPP for Ostertagia ostertagi?

Answer 5

~21 days

Question 6

What is the site of infection for Ostertagia ostertagi?

Answer 6

abomasum

Question 7

When is pathogenesis typically seen with Ostertagia ostertagi?

Answer 7

Pathogenesis is caused primarily by L₃ becoming an immature adult in the gastric glands

Question 8

Describe the effect Ostertagia ostertagi has on the host (pictured below)

Answer 8

“Morrocan Leather”

Basically this is a thickened hyperplastic gastric mucosa. The lesion is a raised nodule with visible central orifices. The result is shown in the picture. The abomasal folds are often very edematous and sometimes necrosis & sloughing occurs

Question 9

There are two forms of bovine ostertagiosis. Type 1 is also known as:

Answer 9

summer ostertagiosis

Question 10

There are two forms of bovine ostertagiosis. Type 2 is also known as:

Answer 10

winter ostertagiosis

Question 11

Which form of bovine ostertagiosis is commonly seen in calves grazed extensively during their 1st grazing season from July - September, as the result of larvae ingested 3-4 weeks previously?

Answer 11

Type 1 disease (summer ostertagiosis)

Question 12

What is the main clinical sign seen in both Type I and Type II ostertagiosis?

Answer 12

watery diarrhea

Question 13

In which type of ostertagiosis do we usually see bottle jaw? Why?

Answer 13

Type II

Hypoalbuminemia is more marked in type II, which leads to submandibular edema (bottle jaw)

Question 14

For diagnostic purposes, will eggs be present for fecal egg count in Type I or Type II?

Answer 14

Type I eggs will be present.

Type II eggs will frequently be absent, since the parasite is not mature yet.

Question 15

In diagnosing Ostertagia ostertagi, which value would we examine in a plasma sample?

Answer 15

We would look for elevated plasma pepsinogen levels

In clinically affected animals up to 2 years old, these are usually in excess of 3.0 iu tyrosine (normal levels are ~ 1.0 iu in nonparasitized calves)

Question 16

What is an important clinical sign that is not seen Ostertagia ostertagi that is seen in Haemonchus placei?

Answer 16

anemia.

Question 17

How would you go about preventing and treating Type I ostertagiosis?

Answer 17

The cattle should be given anthelminthics and moved to pasture not grazed by cattle the same year.

Question 18

How would you go about preventing and treating Type II ostertagiosis?

Answer 18

Type II disease requires anthelminthics, which are effective against arrested larvae, developing larvae, and adults.

The field where the outbreak originated may be grazed by sheep or rested until the following June.

Question 19

Is the Ostertagia ostertagi life cycle direct or indirect?

Answer 19

direct

Question 20

Describe the life cycle of Ostertagia ostertagi.

Answer 20

• Typical trichostrongyloid eggs pass in feces & develop in fecal pat to L₃ in 2 weeks.
  
  • In moist conditions, L₃migrate onto herbage & are ingested during grazing.
• After ingestion, L₃ exsheaths in the rumen and future development takes place in the lumen of the abomasal gland.
• 2 parasitic molts occur before young adult emerges fromthe gland around 18 days after infection to become sexually mature on the mucosal surface
• Males and females mate, and the female lays eggs
• However, under certain circumstances, many of the ingested L₃ become arrested in development as early L₄ for up to 6 months.
• The L₃ can also survive on pastures over winter, although they tend to die during the spring.