Diagnosis and Control of PGE in Sheep Flashcards
How is PGE diagnosed?
Clinical signs- diarrhoea, weight loss, poor weight gain
Season
Faecal egg counts >750epg
What is the primary species involved in PGE?
Telodorsagia circumcinta
What are the secondary species of nematode involved in PGE?
Trichostrongylus spp
Cooperia spp
How should control be approached?
Not one programme fits all- tailor
Combine good management and effective use of anthelmintics
What two stages are of intervention strategies?
1) intervention strategies that target pre-parasitic stages
2) intervention strategies that target parasitic stages in host
How can intervention of pre-parasitic stages be done?
Faecal removal- not practical for ruminant system
Grazing management
How can you intervene in parasitic stages of host?
Anthelmintics
Breeding for genetic resistance
Vaccination- not yet developed
When can anthelmintics be used?
Treatment of disease
Prophylaxis
Reduces transmission
Reduces pasture challenge
How can use of anthelmintics increase resistance?
Repeated treatments increases resistance
What are the 4 anthelmintics with a broad spectrum which kills all nematodes involved in PGE?
1) Benzimidazole- 1-BZ
2) Levamisole- 2-LV
3) Avermectin/Moxidectin- 3-ML
4) Monepantel- 4-AD
Describe a basic good practice for control of PGE
Workout a control strategy for particular enterpise
Quarantine incoming animals (especially tups)
Test for anthelmintic resistance
Administer drugs correctly
Use anthelmintics only when necessary
Chose the right anthelmintic
Use good management
What is the definition of clean pasture and safe pasture?
Clean- not grazed by sheep for previous 12 months
Safe pasture- used previous year but safe by beginning of June
How else can management be achieved?
Rotation with crops of other stock
