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Caprine and Ovine Brucellosis groups infection of small ruminants by Brucella
melitensis and in a less extent B. abortus. Both are severe zoonosis, B. melitensis is known as the 'Malta' or 'Mediterranean' fever
in humans and B. abortus is also known as 'Bang' disease.
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Classification
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OIE, List B disease
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Susceptible species
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B. melitensis mostly affects ovine and caprine
very contagious to humans, contagious to cattle and less commonly horses
and pigs.
B. abortus mainly affects cattle but it can passes to a number of species
including small ruminants and less commonly pigs and humans.
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Distribution
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Ovine and caprine brucellosis is mainly present in the Mediterranean region,
it also present in some Asian, African and Central Amercian countries. It is
seems top be anecdotic in the Pacific Region, it has not been recorded in
French Polynesia since 2000 and in Guam since 1993 and other countries never
reported it.
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Clinical signs
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Ovine and caprine brucellosis is characterised by:
- Late abortions (2months),
- Stillbirths,
- Weak newborns,
- Placentitis (more common in cows)
- Mastitis,
- Orchitis in males,
- Lameness and hygroma (more common in goats)
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Post-mortem findings
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There is no characteristic lesions.
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Differential diagnosis
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In ovine and caprine abortions due to :
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Specimens required for diagnosis
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In case of clinic suspicion, Brucella spp. should be isolated from
placenta, aborted foetuses, milk, testes or epididymi. Identification
of the bacteria is done by microscopic observation of stained
preparation. PCR techniques are also available.
For screening purposes the rose bengal plate agglutination and complement fixation tests are
used. The serum agglutination test is not considered to be reliable for use in small ruminants. For pooled samples, there are no useful tests such as the milk ring test in cattle.
Allergic skin tests (brucellin allergic skin test ) is also available and can be used as a screening or complementary test in unvaccinated
flocks. Results must then be interpreted in relation to the clinical signs, history, and the results of serological or cultural examination.
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Transmission |
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Animals acquire the disease through oral (ingestion), skin (wound) and
sexual route. The main source of infection are milk and milk products
and abortion material.
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Risk of introduction |
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Ovine brucellosis is more likely to be introduced through importation of
infected animals, semen or embryos. However importation of contaminated milk
and milk products should be also considered mainly because of the zoonotic
risk. Pasteurisation kills the germ.
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Control / vaccines
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A vaccine is available and can be used in infected areas.
The best option for eradication of the disease is testing and removal
of positives.
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| References
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- Brucellosis caused by B.
ovis, In Veterinary Medicine, Saunders, Eight ed,
1997, London p. 810-812
- Office International des Epizooties, 2002
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Office
Vétérinaire Fédéral Suisse
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