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375 bytes removed ,  18:59, 24 August 2010
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sufficient supervision should be given at lambing time to ensure adequate intakes of colostrium and the maintenance of good hygiene.
 
sufficient supervision should be given at lambing time to ensure adequate intakes of colostrium and the maintenance of good hygiene.
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Lamb dysentery can be controlled through vaccination against clostridial diseases. Before the advent of modern vaccines,
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Lamb dysentery can be controlled through vaccination against clostridial diseases. Before the development of modern clostridial vaccines in the 1970s, catastrophic losses of up to 30% of the lamb crop could occur due to lamb dysentery<sup>lewis</sup>. The vaccines used today have several components, making them effective against a variety of clostridial diseases and, for some vaccines, ''Pasteurella''. The vaccines consist of toxoids, which are inactivated forms of the toxins produced by clostridial organisms. The principles of vaccination are the same whether a clostridium-only or ''Pasteurella''-combined product is used: a sensitising dose must be given 4-6 weeks before a second confirming does<sup>lewis</sup>. As immunity wanes over a period of a year booster doses are required annually. Therefore, ewes should receive the primary vaccination course before entering the breeding flock and an annual booster approximated about six weeks before lambing. This timing of the booster vaccination affords passive protection to lambs until around sixteen weeks of age. Lambs born to unvaccinated ewes should themselves be vaccinated at between 3 and 12 weeks old, with a second injection given at least four weeks later.
losses from clostridial diseases could
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be cata-strophic, on occasion running
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at over 30 per cent. By the mid-1970s,
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efficient multicomponent vaccines
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were widely available and in the mid-
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1980s the clostridial components were
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combined with multicomponent pasteurella
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antigens. Clostridial vaccines
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are, except for the C chauvoei component,
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directed at the toxins produced
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by the various pathogenic members of
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the clostridial family. Referred to as
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toxoids, they are inactivated and
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require an adjuvant for better stimulation
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of the immune system.
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Whether a straight clostridial vaccine
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or a combined vaccine is used, the principles
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underlying efficacious vaccination
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programmes are identical. For
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effective protection of sheep, of whatever
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age, a primary course of two
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doses, administered four to six weeks
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apart, is required. The first dose can be
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considered a sensitising dose and, the
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second, the confirming dose. Immunity
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wanes over a period of a year and,
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consequently, booster doses are
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required annually.Before ewes enter the breeding flock, they should be given two vaccinations separated by an interval of 4-6 weeks. An annual booster should be given about six weeks before lambing to afford passive protection to lambs until around sixteen weeks of age. Lambs born to unvaccinated ewes should themselves be vaccinated at between 3 and 12 weeks old, with a second injection given at least four weeks later. Good husbandry is also critical to the control of lamb dysentery.
      
==Links==
 
==Links==
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