Revision of PGE Flashcards
What parasite is primarily responsible for causing PGE in sheep in the UK?
Telodorsagia Circumcinta
What parasites of the abomasuem have a cervical papillae at the head end of the worm?
Haemonchus contortus and telodorsagia circumcinta
What SI intectine parasite is coiled?
Cooperia spp
What parasite has a charecteristic ‘notch’ at the head end of the worm?
Trichostronylus spp
What is the typical length of a GI nematode egg?
90um
What parasite is found in the LI is 5-6cm long and divided into a long hair like anterior region and a shorter thicker posterior region. Has distinctive yellowins ‘lemon’ shaped eggs
Trichuris spp adult female worms
What GI parasite causes disease in young lambs in may?
Nematodirus battus
What stage of haemonchus contortus is responsible for causing anaemia in lambs?
Adults
How does PGE effect lambs?
Depressed apetite which reduces feed intake and growth rate
Permanent damage to the gut which reduces the absorption of nutrients and causes diarrhoea
Impaired mineral retention causing a small skelton
Reduced protein metabolism reducing muscle growth and carcase quality
What are the clinical signs and sub-clinical signs of PGE?
Clinical
- Profuse watery diarrhoea
- Weight loss
- Inappetance
- Dehydration
- Death
Sub-clincal
- Poor weight gain
- Reduced appetite
- Reduced feen intake
- Loss of plasma proteins into GI tract
How is PGE diagnosed?
Clinical signs
Diagnosis
FEC- over 750 EPG
What worms that cause PGE in sheep are found in the abomasum, small intestine and large intestine?
Abomasum- Haemonchus contortus, telodorsagia circumcinta, trichostrongylus axei
Small intestine- Nematodirus spp, Trichostrongylus spp, Cooperia
LI- chabertia spp, Oesophagostomum spp, Trichuris spp
What is the pre-patent period of trichostrongylus spp?
3 weeks
When do telodorsagia circumcinta hypobiose?
In the abomasum as L4
What factors influence epidemiology of PGE?
Source on infection- PPR, Hypobiosis of larvae, Overwinterted L3
Development and survival of free living stages is key- Development of eggs to L3 in envrionment, survival of L3 on pasture
Host susceptiblity
When is the PPR rise of eggs from ewes?
PPR from Jan to May/June
When do overwintered L3 graudually die by?
June
When does amount of L3 peak?
Mid July
What is the name for the barbers pole worm?
Haemonchus Contortus
What is the pathogenesis of Haemonchosis?
Adults are voracious blood feeders
Erosion of the abomasal wall
Severe haemorrhagic gastritis
Severe anaemia
Oedema
Weight loss
How can anaemia be best assed in sheep?
Animals eyelids
Describe the epidemiology of Haemonchus?
L3 cannot over winter
PPR from ewes is main source of pasture contamination
Outbreaks in late summer
How can haemonchus be diagnosed?
Clinical signs- anaemia
Season
Feacal egg counts
What parasite often looks like cotton wool?
Nematodirus battus
Describe the pathogenesis of Nemarodirus battus?
Developing L5 destroy mucosa
Catarrhal enteritis
Villous atrophy
Fluid and nutrient absorption disrupted
2000 worms can cause clinical disease
What are the clinica signs of Nematodirus battus?
Sudden explosive outbreaks of acute, watery diarrhoea
Inappetence and dehydration
Abdominal pain, weight loss
Disease in lambs 4-12 weeks
Disease often starts in PPP
Over 500 heavy infestation
Describe the epidemiology of Nematodirus battus?
L3 develops in egg over summer
Overwintered as larvated egg
Requires specific hatching requirments- exposure to prolonged period of chill, exposure to mean temp of 10 degrees
When is the peak of L3 on pasture for nematodirus battus?
Emergence en masse in the spring
