Ostertagia

Question 1

Where are Ostertagia Ostertagi found?

Answer 1

Cattle abomasum - parasitic gastritis - temperate regions

Question 2

What is the morphology of Ostertagia?

Answer 2

around 1cm, slender, pinky-brown
fine cervical papillae, males have spicules and bursa

Question 3

What is the life cycle?

Answer 3

Direct, trichostrongyle egg
L1-3 in faecal pat => rain = L3 on pasture consumed by calves => abomasum - burrows into gastric glands => L4 => L5 => emerge into lumen of abomasum=> emerge as adults and females lay eggs

Question 4

What is the Pre patent period of ostertagia?

Answer 4

3weeks

Question 5

how does ostertagia cause damage?

Answer 5

40,000+ = infection
damage by emerging in gastric glands - damage parietal cells = reduced acid, increased pH, loss of bacteriostatic effect and stop of pepsinogen conversion to pepsin

Question 6

What are the clinical signs?

Answer 6

profuse water diarrhoea
weight loss
loss of appetite

Question 7

What is the difference between type 1+2 ostertagiosis?

Answer 7

type 1 = 1st grazing season - summer, calves
type 2 = yearling calves - late winter/early spring, involves hypobiosis, high mortality

Question 8

What is hypobiosis?

Answer 8

Arrested development of L4 within the host due to a trigger

Question 9

Factors affecting development of pre-parasitic stages?

Answer 9

-temp
-humidity(rainfall)
-dispersion from faecal pat

Question 10

Factors affecting survival of L3?

Answer 10

• ensheathed?
  -Temp, mositure
• Limited food reserves
• limited lifespan

Question 11

Factors affecting hypobiosis?

Answer 11

temp

Question 12

Host factors?

Answer 12

-age
-immune status
-Over dispersion

Question 13

What is the diagnosis of ostertagia?

Answer 13

-clinical signs
-season
-grazing history
-raised plasma pepsinogen levels