Revision of PGE Flashcards
(26 cards)
Severity of PGE disease depends on which 3 factors?
- Concurrent infection
- Nutritional status of the sheep
- Development of the immune response
What are the typical clinical signs of PGE?
- Profuse watery diarrhoea
- Weight loss
- Inappetence
- Dehydration
- Death
Which animals are most affected by PGE?
First season grazing lambs
Which worms cause PGE in the abomasum?
- Teladorsagia circumcincta
- Trichostrongylus axei
- Haemonchus contortus
Which worms cause PGE in the small intestine?
- Nematodirus battus
- Cooperia spp
- Trichostrongylus spp
Which worms cause PGE in the large intestine?
- Chabertia spp
- Oesophagostomum spp
- Trichuris spp
When does PGE type 1 disease occur?
Mid-summer onwards
What can be used to diagnose PGE?
Clinical signs
Faecal egg counts of 750epg
What is the primary PGE causing species?
Teladorsagia circumcincta
Describe the typical trichostrongyle life cycle
- Eggs passed in faeces
- Develop in the faecal pat
- L1 hatch and feed on the bacteria in the faecal pat, moult to L2 and L3 which is ensheathed
- Sheep eat L3 which are swallowed to the abomasum
- Burrows into gastric glands
- Develops to L4 and L5
- L5 (immature adults) emerge, into lumen of abomasum
What is the PPP of trichostrongylus?
3 weeks
What are the 3 sources of PGE infection?
- Peri-Parturient Rise (PPR) in ewes
- Hypobiosis of larvae
- Overwintered L3
Overwintered L3 does out by…?
June
The peak number of eggs on pasture occurs in ?
July/August
The PPR occurs in?
April/May
Name the Barbers pole worm
Haemonchus contortus
Describe some features of Haemonchus contortus
- Spiral gut and ovaries in the female
- Cervical papillae
- Bursa
- Abomasum
Describe the pathogenesis of infection with Haemonchus contortus
- Erosion of abomasal wall
- Severe haemorrhagic gastritis
- Severe anaemia
- Oedema
- Weight loss
When does a Haemonchus disease outbreak occur, what is the main cause?
- Late summer
- Ewe is the main source of pasture contamination (PPR)
- L3 do not survive the winter
What are the clinical signs of a Nematodirus battus infection?
Sudden (explosive) outbreaks of acute, watery diarrhoea
Inappetence, dehydration (thirsty!), abdominal pain, weight loss
Which animals are affected by Nematodirus battus?
Lambs of 4-12 weeks old
Describe the pathogenesis of Nematodirus battus
- Developing L5 destroy the mucosa
- Catarrhal enteritis
- Villous atrophy
- Fluid and nutrient absorption disrupted
Describe the epidemiology/life cycle of Nematodirus battus
- L3 develops in the egg over the summer
- Overwinters as larvated egg
- Emergence of L3 en masse in the spring
- L3 on pasture are the infective stage
What are the specific hatching requirements of an overwintered Nematodirus battus egg?
- Exposure to prolonged period of chill
- Exposure to mean day/night temperature of 10 degrees
