Day 2: Trichostrongyle Nematode Flashcards
Where is trichostrongyle relevant
Worldwide
Which species is found in the US
Haemonchus Contortus
Ostertagia Ostertagia
Trichostrongylus axei
Which species is found in Europe
Cooperia
Ostertagia
Trichostrongylus
Which species are Trichostrongyles most prevalent
Ruminants
Which species does Haemonchus occur
All ruminants
How are animals infected with Haemonchus
Grazing and pick up L3 larvae on pasture
What are some characteristics of Haemonchus in sheep
Severe anemia
Young lambs more susceptible
Older animals acquire immunity
Infected lambs may die
What are some characteristics of Haemonchus in cattle
Develop more chronic disease
Have impaired growth and weight gain
Where do Haemonchus adult worms live in the ruminant
Abomasum
What is the structure of the adult Haemonchus
Wire worm, small and thin
2.5-3 cm long
Barber pole appearance due to blood sucking
GI tract is filled with blood and is wrapped around the reproductive structures which are white
What is the clinical pathology with Haemonchus
Anemia is the most important finding
Anemia can occur in the absence of eggs in feces since L4 stage also sucks blood
Hypoalbuminemia ffrom the GI tract
Abomasum shows damage to the mucosa
Frank bleeding from GI tract
Coagulated blood found in abomasum
What are the clinical findings with Haemonchus
Anemia
Pale MM
Lethargy
Weakness
Lag behind flocks
Diarrhea
Scant dark feces if severe (can look like constipation)
What is the mosphology of Ostertagia
Small slender brown worms, less than 14mm
Where are adult ostertagia found in ruminants
Abomasum
Where is Ostertagi most economically important
US
How do Ostertagia infect ruminants
Grazing L3 on pasture
Arrested development (hypobiosis) at L4 stage
Remain in L3 in abomasum during winter
Once spring arrives, arrested larvae resume development
How is pasture contaminated by Ostertagia
Arrested larvae resume development in ewes
Overwintering larvae in pasture “mat”
What is the clinical pathology for Ostertagia
Hypoalbuminemia and Protein losing enteropathy (PLE)
What is the clinical presentation for Type I Ostertagia
Young cattle grazing on pasture from July-October
L3s develop to adults in 3-4 weeks
Anorexia
Weight loss
Diarrhea
What is the clinical presentation for Pre-Type II Ostertagia
No clinical signs
Arrested at L4 stage of development
Winter months
What is the clinical presentation for Type II Ostertagia (Spring Rise)
Emergence and maturation of arrested L4 to adults
See signs in 10% of group (usually immunocompromised young cattle)
Diarrhea (intermittent)
Anorexia
Edema (hypoproteinemia)
Rough hair coat
What are exam findings in ruminants with ostertagia
Hypoproteinemia
Mild anemia due to tissue damage with serum leakage
Bottle jaw or submandibular edema
Lethargy
Weakness
Poor body condition
Diarrhea or scant feces
Anemia is not as severe
How long is the pathogenesis in early stage (Phase I) for Ostertagia
1-17 days after infection
What occurs during Phase I of Ostertagia infection
L3 exsheath in rumen
Pass to abomasum
Penetrate gastric gland
Molt twice to L4 and L5 and grow
Primary nodule forms that is hyperplastic due to inflammatory response
Arrest or hypobiosis occurs at L4
