Difference between revisions of "Ovine Brucellosis"

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== Introduction ==
Also Known As: '''''Ram Epididymitis''''' — '''''Orchitis''''' — '''''Ovine Contagious Epididymitis''''' — '''''Brucella ovis Epididymitis'''''. 
 
  
Caused By: ''[[Brucella ovis]]'' and ''[[Brucella melitensis]]''
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This is a disease in sheep caused by either ''[[Brucella melitensis]]'' or ''[[Brucella ovis]]''. ''B. mellitensis'' also causes disease in goats, but ''B. ovis'' affects only sheep. It is a disease that causes abortion, stillbirths and the birth of weak lambs and is prevalent in Eurpoe, America and Australia.
  
==Introduction==
 
Ovine brucellosis causes '''reproductive''' disease in sheep, mainly in '''rams'''.
 
  
''B. ovis'' is the least virulent of all the [[Brucella species|''Brucella'' species]].
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== Clinical Signs ==
  
The disease is on List B of the ''Office International des Epizooties'' [http://www.oie.int/ (OIE)]
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''B. mellitensis'' is more severe in goats than sheep. Late abortion, still births or births of weak lambs are seen. With ''B. ovis'', clinical signs in ewes are rarely seen and abortions, stillbirths and weak lambs are rare. Signs are seen mainly in rams and include [[Ovine Epididymitis|epididymitis]] and orchitis.
It is therefore '''notifiable''' to the OIE.
 
  
==Signalment==
 
The disease is unique to sheep.
 
  
==Distribution==
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== Diagnosis ==
Present in all countries where sheep are intensively farmed. It is transmitted mainly through '''semen''' but shedding is unreliable.
 
  
Ewes can also act as indirect vectors for brucellosis if they mate with both an infected and uninfected ram during the same oestrus cycle.
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Diagnosis is by complement fixation, culture of organism or demonstration of the organism in tissue.
  
Abortion materials and vaginal discharge also contain [[Brucella species |''Brucella'']] organisms
 
  
Brucellosis is not considered zoonotic.
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== Control ==
  
==Clinical Signs==
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Test and slaughter is applied where the disease is exotic.  
'''Epididymitis''' in rams with '''swelling''' and enlargement of [[Testes and Epididymis - Anatomy & Physiology |'''testes''']], scrotum, [[Penis - Anatomy & Physiology |'''penis''']] and prepuce. Decreased reproductive performance will be noticed due to '''impaired [[Spermatogenesis and Spermiation - Anatomy & Physiology |spermatogenesis]]'''.
 
  
Testicular '''atrophy''' occurs in chronic infections.
 
  
Occasionally also '''abortion''' in ewes and weak lambs. This only occurs due to placental necrosis in ewes exposed in the first two trimesters of pregnancy.
 
  
==Diagnosis==
 
Palpation of the testes is suggestive but not definitive.
 
 
Specific '''immunofluorescent''' staining of semen smears is confirmatory.
 
 
''Brucella'' organisms can also be '''isolated''' from the epididymis and accessory sex glands at necropsy, although excretion is intermittent so false negatives are not uncommon.
 
 
[[ELISA testing |'''ELISA''']] and '''Complement Fixation''' are also commonly used for serological diagnosis.
 
 
==Treatment==
 
'''Antibiotic''' therapy is very expensive, prolonged and ineffective.
 
 
==Control==
 
'''Testing and culling''' of breeding stock is essential to ensure carriers are not present within a flock.
 
 
Vaccination is available against both ''Brucella'' species, but ''B. ovis'' vaccines are only widely used in New Zealand.
 
Any vaccination will interfere wih serological diagnosis and this should be considered.
 
 
{{Learning
 
|literature search = [http://www.cabdirect.org/search.html?q=title%3A+%28Ovine+Brucellosis%29/ Ovine Brucellosis Publications]
 
 
|flashcards = [[Ovine Brucellosis Flashcards]]
 
}}
 
 
==References==
 
<references/>
 
{{CABI source
 
|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=90731&loadmodule=datasheet&page=2144&site=160 brucellosis (''Brucella ovis'')]
 
|date =6 June 2011
 
}}
 
<br><br><br>
 
 
{{review}}
 
 
{{OpenPages}}
 
 
[[Category:CABI Expert Review]][[Category:CABI AHPC Pages]]
 
 
[[Category:Reproductive Diseases - Sheep]][[Category:Reproductive System - Pathology]]
 
[[Category:Reproductive Diseases - Sheep]][[Category:Reproductive System - Pathology]]
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[[Category:To Do - Steph]]

Revision as of 21:33, 5 June 2011

Introduction

This is a disease in sheep caused by either Brucella melitensis or Brucella ovis. B. mellitensis also causes disease in goats, but B. ovis affects only sheep. It is a disease that causes abortion, stillbirths and the birth of weak lambs and is prevalent in Eurpoe, America and Australia.


Clinical Signs

B. mellitensis is more severe in goats than sheep. Late abortion, still births or births of weak lambs are seen. With B. ovis, clinical signs in ewes are rarely seen and abortions, stillbirths and weak lambs are rare. Signs are seen mainly in rams and include epididymitis and orchitis.


Diagnosis

Diagnosis is by complement fixation, culture of organism or demonstration of the organism in tissue.


Control

Test and slaughter is applied where the disease is exotic.