Trichostrongylosis of ruminants and lagomorphs.

Question 1

What is the morphology of Trichostrongylosis in ruminants?

Answer 1

1-3 cm, hair-like, prominent bursa

Question 2

What type of life cycle do Trichostrongylosis have?

Answer 2

All have a direct life cycle with infective L3 larva (no migration)

1. Preparasitic phase: L1 hatches from egg and develops to infective L3 in environment. Migrates onto vegetation making them available for grazing animals. They are found in a film of moisture.
2. Parasitic phase: non-migratory. Develops into adults in mucosa of abomasum or small intestine.

Question 3

What occurs during the preparasitic phase of Trichostrongylosis of ruminats?

Answer 3

L1 hatches from egg and develops to infective L3 in environment

Question 4

Trichostrongylosis of ruminats - How do infective L3 larvae become available for grazing animals?

Answer 4

They migrate onto vegetation and are found in a film of moisture

Question 5

What happens during the parasitic phase of Trichostrongylosis of ruminats?

Answer 5

Non-migratory; develops into adults in mucosa of abomasum or small intestine

Question 6

What are the common treatments for Trichostrongylosis of ruminats?

Answer 6

Benzimidazoles, Levamisole, Ivermectin

Question 7

What methods are used for diagnosing Trichostrongylosis of ruminats?

Answer 7

Necropsy, coprological/faecal examination - presence of strongyle-type eggs

Question 8

To which order do Trichostrongylosis belong?

Answer 8

Strongylida

Question 9

Trichostrongylus spp.

Answer 9

• T. axei – ru, eq, su – abomasum/stomach
• T. colubriformis – ru – SI
• T. vitrinus – ru – SI
• T. capricola – small ru (goat, sheep) – SI
• T. retortaeformis – rabbit and hare – duodenum

Question 10

Pathogenesis of Trichostrongylus spp.

Answer 10

T. axei: L3 penetrate between gastric glands and their growth and development causes nodular lesions. Rise of pH will happen in abomasum, increased permeability of the mucosa.
Intestinal species: L3 penetrate between the epithelial glands, making tunnels between the epithelium and lamina propria. When they become adults 10-12 days later they cause erosions, causing haemorrhages and loss of plasma proteins.

Question 11

CS of Trichostrongylus spp.

Answer 11

• Light infections: asymptomatic or poor appetite, slow growth rates, soft feces.
• Heavy infections (>10,000 worms): serious black/green watery diarrhea.

Question 12

Epizootiology of Trichostrongylus spp.

Answer 12

• Not often primary pathogens.
• Hypobiosis (arrested development) occurs at L3 stage and is a very important controlling feature of life cycles in temperate areas of the world.
• L3 are able to survive both heat and cold.

Question 13

Egg of Trichostrongylus spp.

Answer 13

Medium, ovoid, symmetrical, 2 thin shells, unembryonated, many blastomers, grey

Question 14

List species of Nematodirus with their specific hosts.

Answer 14

Nematodirus filicolis — sheep, goat

Nematodirus battus — sheep

Nematodirus helvetianus — cattle

Nematodirus spathiger — sheep, goat

Nematodirus abnormalis — sheep, goat

Question 15

Which species look similar to Nematodirus helvetianus and Nematodirus spathiger?

Answer 15

Marshallagia marshalli

Question 16

Where are Nematodirus species found in the final host?

Answer 16

Small intestine.

Question 17

Describe the morphology of Nematodirus spp.

Answer 17

• Up to 2.5 cm.
• Slender, long worm, transverse striations, female has pointed tails, cephalic vesicle present.

Question 18

Describe reproductive features of male and female Nematodirus spp.

Answer 18

• Female: tail spine more blunt.
• Male: long slender spicules fused at tip.

Question 19

Describe the egg of Nematodirus spp.

Answer 19

Extra large, oval, symmetrical eggs, 2 thin shells, unembryonated, 8 blastomeres, greyish colour.

Question 20

What clinical signs are caused by Nematodirus spp.?

Answer 20

Diarrhea, rapid dehydration.

Question 21

What is important about the epidemiology of Nematodirus spp.?

Answer 21

• L3 has an ability to survive from year to year enclosed in their protective eggs.
• Arrested development (hypobiosis) is recorded in sheep.

Question 22

What are the species of Haemonchus and their hosts?

Answer 22

Haemonchus contortus — sheep, goat

Haemonchus placei — cattle

Question 23

Where do Haemonchus spp. locate in the final host?

Answer 23

Abomasum.

Question 24

What is the size of Haemonchus worms?

Answer 24

10–30 mm.

Question 25

Describe the morphology of Haemonchus spp.

Answer 25

* Reddish due to blood sucking; have a lancet in their buccal capsule. * Distinct copulatory bursa with asymmetrical dorsal lobe and Y-shaped dorsal ray.

Question 26

What is the life cycle duration for Haemonchus contortus and Haemonchus placei?

Answer 26

* H. contortus: 2–3 weeks * H. placei: 4 weeks

Question 27

Describe the eggs of Haemonchus spp.

Answer 27

Medium, oval, symmetrical eggs with 2 thin shells, unembryonated, few blastomeres, light brown/gray.

Question 28

What is the pathogenesis caused by Haemonchus spp.?

Answer 28

* Haemorrhagic anemia. Primary pathogens in parasitic gastroenteritis. * **Peracute haemonchosis:** Sudden deaths in sheep due to ingestion of large numbers of infective larvae. * **Acute haemonchosis:** Sudden onset anemia and hemorrhagic lesions. * **Chronic haemonchosis:** Daily loss of small amounts of blood, worsened by poor dietary protein.

Question 29

What are the clinical signs of Haemonchus infection?

Answer 29

**Acute:** anemia, edema, weakness, dark feces, wool loss. **Chronic:** weight loss, lethargy, mild anemia.

Question 30

What are the species of Ostertagia and their typical hosts?

Answer 30

Ostertagia ostertagi — cattle Ostertagia circumcincta — sheep, goats Ostertagia trifurcata — sheep, goats

Question 31

Where do Ostertagia spp. locate in the final host?

Answer 31

Abomasum.

Question 32

What is the size of Ostertagia worms?

Answer 32

10 mm.

Question 33

Describe the morphology and lifecycle features of Ostertagia spp.

Answer 33

Reddish/brown worms. Produce ostertagiosis. Hypobiosis can occur in the lifecycle (arrested development at L4).

Question 34

What is the prepatent period for Ostertagia spp.?

Answer 34

21 days

Question 35

Describe the eggs of Ostertagia spp

Answer 35

Medium, oval, symmetrical eggs with 2 thin shells, unembryonated, many blastomeres, gray.

Question 36

Pathology in Ostertagia ostertagi infection:

Answer 36

* Primary pathogens in parasitic gastroenteritis. * Ostertagia ostertagi is the most common cause of parasitic gastritis in grazing cattle. * Damage of gastric gland epithelium; due to growth of developing larvae in gastric glands — not blood-sucking behavior.

Question 37

What factors influence the epidemiology of Ostertagia spp.?

Answer 37

Temperature and moisture affect survival and development of early stages of life stages. Important: * The different ways pasture is used * Influence on seasonal arrested development * Influence of immune response on infection and disease

Question 38

What are the clinical signs of Ostertagia infection?

Answer 38

* **Type I:** Occurs in young cattle grazing pastures for the first time. * **Type II:** Results from arrested L4 larvae starting up their development to adults and leaving gastric glands. Both types cause diarrhea, anorexia, dehydration, thirst, weight loss, submandibular edema, anemia.

Question 39

Where is Ostertagia infection common geographically?

Answer 39

Temperate areas.

Question 40

What are the species of Cooperia and their hosts?

Answer 40

Cooperia curticei — sheep, goats Cooperia oncophora — cattle Cooperia pectinata — cattle Cooperia punctata — cattle Cooperia surnabada — cattle, sheep

Question 41

Where do Cooperia spp. reside in the final host?

Answer 41

Small intestine

Question 42

What is the life cycle duration of Cooperia spp.?

Answer 42

15–18 days.

Question 43

What is the size of Cooperia worms?

Answer 43

5–9 mm.

Question 44

What clinical signs are caused by Cooperia infection?

Answer 44

Diarrhea, weight loss, anorexia, poor weight gains.

Question 45

What is important in the epidemiology of Cooperia spp.?

Answer 45

Winter hypobiosis at L4 stage in the northern hemisphere.

Question 46

Pathology of Mashallagia mashalli

Answer 46

Form nodules in intestine.

Question 47

Clinical signs of Mashallagia mashalli

Answer 47

Diarrhoea, weight loss.

Question 48

What is the pathogenesis of Graphidium strigosum and Obeliscoides cuniculi in rabbits and hares?

Answer 48

* Both feed on blood. * Both are located in the mucosa of the stomach. * In massive infections, they cause massive or hemorrhagic inflammation.

Question 49

What are the species responsible for trichostrongylosis in rabbits and hares, and where are they located?

Answer 49

* Graphidium strigosum — stomach * Trichostrongylus retortaeformis — duodenum * Obeliscoides cuniculi — hares only (stomach)

Question 50

What clinical signs are seen in trichostrongylosis of rabbits and hares?

Answer 50

* Usually asymptomatic. * In strong infections: hemorrhagic or chronic bluetongue gastritis, anemia, diarrhea, weight loss. * Non-wormed pups may die.

Question 51

What is the treatment for trichostrongylosis in rabbits and hares?

Answer 51

* Fenbendazole * Ivermectin

Question 52

How is trichostrongylosis diagnosed in rabbits and hares?

Answer 52

* Detection of eggs via coprological examination * Necropsy — direct observation of worms

Question 53

Trichostrongylosis of ruminats is caused by:

Answer 53

* Trichostrongylus spp * Nematodius spp * Marshallagia marshali * Haemonchus spp * Ostertagia spp * Cooperia spp