Ostertagia ostertagi (1) Flashcards
What are the host?
Cattle
What’s important about Ostertagia ostertagi?
It is the most important parasite of cattle in USA
Describe an adult
1 cm
Abomasal surface
Describe an egg
Thinshelled
Oval
85 micro m
Describe the life cycle
Direct
L3 enter abomasal glands - emerge as immature adults
Adults live in abomasum
Type II Ostertagiosis
Type I Ostertagiosis
L3 can survive on pastures over winter
Tend to die during the spring
PPP: 21 days
Arrested L4: up to 6 months
Describe type II Ostertagiosis
Emergence of many immature adults at one time after arresting
Winter Ostertagiosis
In calves following 1st grazing season with arrested L4
Profuse watery diarrhea - intermittent
More “Bottle jaw”
Clinical disease low, mortality high unless treatment instituted
Describe type I Ostertagiosis
Emergence of immature adults over an extended period of time
What is the site of infection
Abomasum
What is the common name?
Brown Stomach Worms
Describe the Pathogenesis
Gives rise to extensive pathological and biochemical changes and several clinical signs
Maximal when parasites are emerging from gastric gland
Caused primarily by L3 to immature adult in gastric glands
Thickened gastric mucosa: raised nodules - “Moroccan leather”
Increased plasma pepsinogen
Reduction in functional gastric gland mass responsible for the production of the highly acidic Proteolytic gastric juice (parietal cells - produce HCl)
Cells replaced by rapidly dividing undifferentiated non-acid-secreting cells
Changes occur in the parasitized glands: distend gland, changes
spread to non-parasitized
glands
- End result: thickened hyperplastic gastric mucosa
Raised nodule with visible central orifices, very edematous
Necrosis and sloughing
Substantial leakage of endogenous protein
Describe the clinical signs
Inappetance
Weight loss
Diarrhea
Submandibular edema (bottle jaw)
Light infections - suboptimal weight gains
How do you diagnose Ostertagia ostertagi?
Clinical signs
Fecal egg counts
- Type I have EPG - Type II often negative
L3 identification
Plasma pepsinogen levels elevated
% adults to larvae high in type I and low in type II
Necropsy
Seasonality
Grazing history
How do you treat and prevent Ostertagia ostertagi type I?
Responds well to Anthelmintics
More cattle to “safe pasture”
How do you treat and prevent Ostertagia ostertagi type II?
Require Anthelmintics effective against arrested L4, larvae and adults
How do you prevent Ostertagia ostertagi?
Limiting exposure to infection
Creating “safe pasture”
Exposure is needed to acquire immunity
