Weight loss in sheep Flashcards
what bacteria causes joint ill in sheep?
most commonly strep dysgalactiae.
how is lameness scored in sheep?
what is the 5 point plan for lamness in sheep?
0 – even weightbearing, even rhythm, flat back. Cannot identify a limb to be lame on
1 –uneven walking, obvious head nods, shortened strides
2 – non-weightbearing on one or more limbs
5 point plan:
- build resilience - cull
- establish immunity - vaccinate
- reduce disease challenge - ** avoid, treat, quarentine**
what is Ovine pulmonary Adenocarcinoma?
what are the clinical signs?
how is it diagnosed?
- Caused by a betaretrovirus called Jaagsiekte sheep retrovirus (JSRV)
- Commonly known as Jaagsiekte, ovine pulmonary carcinoma, sheep pulmonary adeomatosis.
- Tumours grow in lungs so impair lung function
- Tumours may secrete fluid, further impairing lung function
Clinical signs:
Chronic wasting
Progressive respiratory distress
Appetite remains good
Leads to death
Incubation can be months or years
Very little serological response
Pre-clinical detection will be vital for effective OPA control and potential elimination
- Ultrasound scanning - hyperechoic lesions
what is Maedi Visna?
what does it cause?
how is it spread?
Multi-organ disease
Lentivirus, retrovirus family
Icelandic term for “Dyspnoea-Wasting”
- Maedi – slowly progressive interstitial pneumonia of adult sheep
- Visna – slowly progressive encephalomyelitis of adult sheep – also arthritis and mastitis
Spread:
- Horizontal transmission by aerosol - biosecurity
- Vertical transmission through colostrum and milk - biocontainment
always introduced by a sheep - close contact
what is Caeseous lymphadenitis?
how is it spead?
what is the pathogenesis?
how is it prevented?
Corynebacterium pseudotuberculosis
Spreads well at shearing, Lasts well in the environment
Superficial infection –> Lymph nodes –> suppurating infection –> haematological spread –> abscesses in internal organs
Prevention is through good hygiene
Efforts continue to develop a UK licensed vaccine
Nematodes are also a cause of weight loss in sheep?
What parasites have a differnet lifecycle and have different control stratergies?
Nematodirus Battus - Overwinters and causes disease before Clinical sings therefore will not show on FWEC - need to predict and treat before signs
Haemonchous contortus - produces lots of larvea and drinks blood of the sheep from the abomasum lining, does not cause diahhroea
What is Border disease?
what are the clinical signs?
Pestivirus
Similar to BVD in cattle
Causes:
* abortion
* still birth
* strange development of primary hair follicles giving halo fibres
* PI’s
* tonic clonic skeletal muscular contractions
* this may look similar to hypomyelinogenesis in CNS
Control: Detect and eradicate!
Trans placental spread: can get PI if infected < 60 days
if infected > 85 days lambs born normal as will have monted an immune response
What does Johnes disease cause in sheep?
when are sheep infected?
what are the clinical signs?
how is johnes disease diagnosed?
A mycobacterial disease, Of the intestines, Which results in poor protein absorption
suggested that infected in first few days of life, as there are gaps in the endothelium that allow the IgG from colostrum to be absorbed, the mycobacterium is large and therefore is able to cross the endothelium during this period
clinical signs: (appear later in life)
- weight loss
- scour
- ill thrift
not seasonal:
johnes = normal globulin (as liver is ok, these are produced here), low albumin (as gut damaged, so. albumin lost)
fascioliasis = Low globulins (liver damaged), Low albumin (damage liver so no protein production, and damaged gut so PLE - lose all protein.)
No treatment
There is a vaccine – which we may not wish to use (not DIVA)
- May reduce shedding sufficiently to act as a firebreak
Control is as Johnes control in cattle (high risk mothers away from lambing pens, prevent infectious faeces out of lamb mouths)
