Difference between revisions of "Ovine Brucellosis"

Revision as of 10:38, 6 June 2011

Bisected testicle form B. ovis ram showing grossly enlarged epididymis with fibrous tissue bands. AFSPH Iowa State

Also Known As – Ram epididymitis – Orchitis – Ovine Contagious Epididymitis – Brucella ovis Epididymitis.

Caused By – Brucella ovis

Introduction

Ovine brucellosis causes reproductive disease in sheep, mainly in rams.

B. ovis is the least virulent of all the Brucella species.

The disease is on Lost B of the Office des International des Epizooties [www.oie.int/ (OIE)]

Signalment

Unique to sheep

Distribution

Present in all countries where sheep are intensively farmed.

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.

Abortion materials and vaginal discharge also contain brucella organisms

Brucellosis is not considered zoonotic.

Clinical Signs

Epididymitis in rams – swelling and enlargement of testes, scrotum, penis and prepuce.

Decreased reproductive performance due to impaired spermatogenesis.

Testicular atrophy occurs in chronic infections.

Occasionally also abortion in ewes and weak lambs. This only occurs in ewes exposed in the first two trimesters or pregnancy, due to placental necrosis.

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 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.

No vaccine is available for B. ovis and vaccination against B melitensis can interfere with serological diagnosis.

References

Animal Health & Production Compendium, Brucellosis (B ovis) datasheet, accessed 06/06/2011 @ http://www.cabi.org/ahpc/

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 [[File:B ovis.jpg|thumb|200px|right|Bisected testicle form ''B. ovis'' ram showing grossly enlarged epididymis with fibrous tissue bands. AFSPH Iowa State]]
-== 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.
+Also Known As – '''''Ram epididymitis''''' – '''''Orchitis''''' – '''''Ovine Contagious Epididymitis''''' – '''''Brucella ovis Epididymitis'''''.
+Caused By – ''[[Brucella ovis]]''
+==Introduction==
+Ovine brucellosis causes '''reproductive''' disease in sheep, mainly in '''rams'''.
-== Clinical Signs ==
+B. ovis is the least virulent of all the [[Brucella species]].
-''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.
+The disease is on Lost B of the ''Office des International des Epizooties'' [www.oie.int/ (OIE)]
+==Signalment==
+Unique to sheep
+==Distribution==
+Present in all countries where sheep are intensively farmed.
+Transmitted mainly through '''semen''' but shedding is unreliable.
-== Diagnosis ==
+Ewes can also act as indirect vectors for brucellosis if they mate with both an infected and uninfected ram during the same oestrus cycle.
-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.
+==Clinical Signs==
+'''Epididymitis''' in rams – '''swelling''' and enlargement of [[Testes and Epididymis - Anatomy & Physiology | '''testes''']], scrotum, [[Penis - Anatomy & Physiology | '''penis''']] and prepuce.
-== Control ==
+Decreased reproductive performance due to '''impaired [[Spermatogenesis and Spermiation - Anatomy & Physiology | spermatogenesis]]'''.
-Test and slaughter is applied where the disease is exotic.
+Testicular '''atrophy''' occurs in chronic infections.
+Occasionally also '''abortion''' in ewes and weak lambs. This only occurs in ewes exposed in the first two trimesters or pregnancy, due to placental necrosis.
+==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.
+No vaccine is available for B. ovis and vaccination against B melitensis can interfere with serological diagnosis.
+==References==
+<references/>
+Animal Health & Production Compendium, Brucellosis (B ovis) datasheet, accessed 06/06/2011 @ http://www.cabi.org/ahpc/
+[[Category:To Do - CABI review]]
 [[Category:Reproductive Diseases - Sheep]][[Category:Reproductive System - Pathology]]
-[[Category:To Do - Steph]]