Infectious (Iceberg) Dx in Sheep Flashcards
Describe common viral, bacterial, protozoal ?
Infectious causes of poor fertility?
- Chlaydophilia abortus AKA Enzootic Abortion of Ewes (EAE)
- Toxoplasma gondii
- * Campylobacter fetus fetus
* Salmonella
* Q fever
* Listeria monocytogenes
* Border disease
* Schmallenberg
* Bluetongue
* (Brucellosis- Brucella ovis)
What do we mean by Iceber diseases?
- Low Clinical Visibility
- Lack of availability of effective diagnostic testing
- High Subclinical PResence
- Economic & Health Impact
Jhone’s dx in sheep caused by ..?
Mycobacterium avium sbsp Paratuberculosis
Lon incubation , no tx
Johne’s seen in?
animals >2.5yrs - weight loss
CLS Johne’s ?
- Chronic weight loss despite normal appetite
- Poor fleece quality
- Bottle jaw in later stages
What is NOT a sign of JOHNES
NO Diarrhoea
What does Johnes indirect consequences?
More susceptible to other infections - mastitis etc
Lambs born to ewes in late stage = poor weight
Transmission of Johne’s?
- Ingestion of contaminated faeces by lambs
- Acquired in utero- less common
- Animals shedding without clinical signs
Jhone’s diagnosis?
Serum albumin and globin
- Profound hypoalbuminaemia
- Normal globulins
- PLE
Serum ELISA
- Low sensitivity & high Sp (high n° false neg)
- Individual testing expensive
Pooled faecal PCR (on cull animals to establish prevalence)
Jhones Control?
- Probably in all UK flocks
- Regular BCS
- Culling
- Testing of thin sheep/culls (PM, Pooled faecal PCR)
- Cull & re-stock with low risk ewes
- Vaccination
- CLOSED FLOCK
What is the agent for Caseous Lymphadenitis? (CLA)
Corynebacterium pseudotuberculosis
Transmission of CLA?
- Direct sheep-sheep during close confirnement or shearing equipment
- highly infectious
- Able to stay in environment for long time
What gross path of CLA?
Abscessation of superficial lymph nodes and LN of internal organs
Transmission of CLA
- sheep:sheep in close conact
- through contaminated equipment
- Rams head lesions whilst fighting
- Aerosol
- Shared dipping
Which superficial LNs affected by CLA?
- parotid, submandibular, popliteal, precrural and
prescapular - Easily spread when abscesses open
- Don’t often show clinical signs
What does Internal CLs cause?
= spread to internal lymph nodes
- thin ewes syndrome
- associated clinical signs e.g. dyspnoea
Diagnosis:
- Blood sample - western blor
- Interferon-Y
-Bacteriology
Tx & Management?
- difficult to treat as ABs can’t penetrate the fibrous capsule/ into abscess to work
PRevention LDA?
- Biosecurity & testing
- Shearing equipment /other equipment
- buy from dx free flock
Management of CLA?
Vaccination- not in UK-wont lead
to eradication
True positive Vs vaccinated
Test and Cull
Test entire flock at repeated
intervals and cull
Describe Ovine Pulmonary Adenocarcinoma/ Jaagsiekte
- Viral-induced Adenomatous lung tumours
- Jaagsiekte sheep retrovirus JRSV
Transmission of OPA?
- Horizontal transmission- ewe to ewe
- Aerosol and infected surfaces
- Prolonged incubation
- Age 2-4
CLS of OPA?
- Non-specific
- Chronic weight loss
- Progressive dyspnoea
- Respiratory distress
- Crackles
- High pitched moist lung sounds
- Death
- Build up of excessive fluid
- Free flowing frothy nasal
discharge - Secondary bacterial infection