Day 2: Trichostrongyle Nematode

Question 1

Where is trichostrongyle relevant

Answer 1

Worldwide

Question 2

Which species is found in the US

Answer 2

Haemonchus Contortus
Ostertagia Ostertagia
Trichostrongylus axei

Question 3

Which species is found in Europe

Answer 3

Cooperia
Ostertagia
Trichostrongylus

Question 4

Which species are Trichostrongyles most prevalent

Answer 4

Ruminants

Question 5

Which species does Haemonchus occur

Answer 5

All ruminants

Question 6

How are animals infected with Haemonchus

Answer 6

Grazing and pick up L3 larvae on pasture

Question 7

What are some characteristics of Haemonchus in sheep

Answer 7

Severe anemia
Young lambs more susceptible
Older animals acquire immunity
Infected lambs may die

Question 8

What are some characteristics of Haemonchus in cattle

Answer 8

Develop more chronic disease
Have impaired growth and weight gain

Question 9

Where do Haemonchus adult worms live in the ruminant

Answer 9

Abomasum

Question 10

What is the structure of the adult Haemonchus

Answer 10

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

Question 11

What is the clinical pathology with Haemonchus

Answer 11

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

Question 12

What are the clinical findings with Haemonchus

Answer 12

Anemia
Pale MM
Lethargy
Weakness
Lag behind flocks
Diarrhea
Scant dark feces if severe (can look like constipation)

Question 13

What is the mosphology of Ostertagia

Answer 13

Small slender brown worms, less than 14mm

Question 14

Where are adult ostertagia found in ruminants

Answer 14

Abomasum

Question 15

Where is Ostertagi most economically important

Answer 15

US

Question 16

How do Ostertagia infect ruminants

Answer 16

Grazing L3 on pasture
Arrested development (hypobiosis) at L4 stage
Remain in L3 in abomasum during winter
Once spring arrives, arrested larvae resume development

Question 17

How is pasture contaminated by Ostertagia

Answer 17

Arrested larvae resume development in ewes
Overwintering larvae in pasture “mat”

Question 18

What is the clinical pathology for Ostertagia

Answer 18

Hypoalbuminemia and Protein losing enteropathy (PLE)

Question 19

What is the clinical presentation for Type I Ostertagia

Answer 19

Young cattle grazing on pasture from July-October
L3s develop to adults in 3-4 weeks
Anorexia
Weight loss
Diarrhea

Question 20

What is the clinical presentation for Pre-Type II Ostertagia

Answer 20

No clinical signs
Arrested at L4 stage of development
Winter months

Question 21

What is the clinical presentation for Type II Ostertagia (Spring Rise)

Answer 21

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

Question 22

What are exam findings in ruminants with ostertagia

Answer 22

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

Question 23

How long is the pathogenesis in early stage (Phase I) for Ostertagia

Answer 23

1-17 days after infection

Question 24

What occurs during Phase I of Ostertagia infection

Answer 24

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

Question 25

How long is the pathogenesis in mid stage (Phase II) for Ostertagia

Answer 25

17-35 days

Question 26

What occurs during Phase II of Ostertagia infection

Answer 26

Immature adults emerge from the glands
Secondary nodules form
Decreased pepsinogen due to damaged chief cells
Decreased HCl due to damaged parietal cells, which increases abomasal pH and increase in bacteria
Hyperplastic epithelium more leaky
Leaking protein into abomasum and PLE
Plasma pepsinogen becomes elevated

Question 27

What are the clinical sign in Phase II of Ostertagia infection

Answer 27

Anorexia
Impaired digestion
Weight loss
Diarrhea
Dehydration
Bottle jaw

Question 28

What is the pathology of Phase II Ostertagia

Answer 28

Moroccan leather appearance to the surface of the abomasum

Question 29

How long is the late phase (Phase III) of Ostertagia

Answer 29

35 days and beyond

Question 30

What occurs during Phase III of Ostertagia

Answer 30

Recovery phase
Animal may die if not treated
Treatments include anthelmintics, antibiotics and supportive care for dehydration

Question 31

What is the pathology of Phase III in Ostertagia

Answer 31

Numerous nodules on abomasum surface
Moroccan leather

Question 32

What is the morphology of trichostrongylus

Answer 32

Small, hair-like worms
Less than 7mm long

Question 33

Which species does Trichostrongyle affect

Answer 33

Cattle
Horses

Question 34

Where do Trichostrongylus live

Answer 34

Small intestines

Question 35

What is the clinical pathology of Trichostrongylus

Answer 35

Hypoalbuminemia
Decreased PCV

Question 36

What are the clinical findings of Trichostrongyles

Answer 36

Severe enteritis if worm burden is high
Anemia
Pale MM
Diarrhea
Lethargy
Weakness
Poor body condition
Bottle jaw

Question 37

How do you diagnose Trichostrongyle infections

Answer 37

Fecal flotation with strongyle-type eggs