Parasitic Gastroenteritis

Question 1

What is PGE?

Answer 1

Parasitic gastroenteritis

Diarrhoea in lambs in late SUmmer

Question 2

Which worms cause PGE?

Answer 2

Teladorsagia circumcincta (main cause)
Trichostrongylus spp
Cooperia

Question 3

What does the pathogenesis of PGE depend on?

Answer 3

Concurrent infections
Nutritional status
Immune response

Question 4

What are the clinical signs of PGE?

Answer 4

Diarrhoea

Lack of weight gain/weight loss

Question 5

What is the main source of pasture contamination? Why is this?

Answer 5

Ewes

Due to peri-parturient rise (reduced immunocompetence around parturition, reactivates hypobiosed larvae)

Question 6

When are eggs shed on pasture? When are they ingested and when do they cause disease?

Answer 6

By ewes in Spring
Ingested by lambs in Summer
Causes disease late Summer

Question 7

Describe the lifecycle of a worm that causes PGE

Answer 7

Adult female mates in abomasum and lays eggs
Eggs excreted and hatch to L1
L1 develop to L2 and L3 using bacteria in faeces
L3 released from faeces by rain splash and onto pasture
Lambs ingest pasture
L3 penetrate gastric glands and develop into L4 and L5
L5 reemerge into abomasum lumen and cycle repeats

Question 8

How do worms negatively affect lambs (4 ways)

Answer 8

Decrease appetite
Impair mineral retention
Cause permanent damage to gut
Reduce protein metabolism

Question 9

How long is the pre-patent period of a worm that causes PGE?

Answer 9

3 weeks