Sheep Disease Schemes

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Sheep Disease Schemes

• C S Parker BVMS DBR MRCVS

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Schemes Available

• Scrapie
• Maedi Visna
• Enzootic Abortion
• Future- Contagious lymphadenitis
• Far future foot rot?

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Scrapie

• What causes it
• What are the signs
• How is it transmitted
• MAFF monitoring
• Scrapie Genotyping

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What causes Scrapie

• ?
• 3 theories
• prion
• genetics

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Diagnosis

• Clinical Signs
• Post mortem

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DEFRA scrapie monitoring scheme

• Voluntary certification scheme
• Holding subject to Veterinary checks
• animals identified
• No case scrapie confirmed for 3 years
• Proportion of cull ewes brain sampled
• Restocked from similar premises

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Clinical Signs

• Itching rubbing and nibbling

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Clinical Signs

• Hyperexcitability
• general trembling
• odd expression

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Clinical Signs

• Inco-ordination

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How is it transmitted

• At birth
• pasture contamination
• Other vectors?

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Scrapie genotyping

• Only one test in animals life
• tested at any age
• blood test
• can be limited to stud rams
• can be combined at VM testing

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How does it work

• 3 codons tested 136 154 171
• Various combinations

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What does it cost?

• Full testing 1-19 36
• Two codons 30
• Codon 171 -13
• Codon 136 - 22

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Maedi Visna

• Chronic disease
• Maedi -chronic pneumonia
• Visna nervous wasting disease

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Clinical Signs

• long incubation
• progressive pneumonia
• nervous form

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transmission

• milk/colostrum
• respiration

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Control Schemes

• Monitoring scheme
• Accreditation scheme

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MV monitoring scheme

• commercial flocks
• Not strict isolation rules
• Not MV accredited
• Same test protocol as accreditation scheme
• Only 1 entry test required

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MV accreditation

• Strict isolation- 2 metres for grazing, 7 days
  time lapse
• May share buildings lt10 days - 2m barrier
• 2 initial tests then bi-annual

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Future schemes

• EAE
• Foot Rot