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Causes: '''''Botulism'''''

Causes: '''''Botulism'''''

== Introduction ==  

== Introduction ==  

''Clostridium botulinum'' is a spore-forming, gram positive bacterium. It is oval with subterminal endospores. ''C. botulinim'' spores survive boiling for hours. '''Botulism''' is caused by the ingestion of the neurotoxin produced by the pathogen.

''Clostridium botulinum'' is a spore-forming, gram positive bacterium.

 

 

The bacterium is oval with subterminal endospores. ''C. botulinim'' spores survive boiling for hours. '''Botulism''' is caused by the ingestion of the neurotoxin produced by the pathogen.

''Clostridium botulinum'' is found ubiquitously in the soil worldwide. It is one of the most lethal substances known on earth as only 1.0 micrograms is the lethal dose for humans. Therefore the disease is zoonotic and a public health issue.

''Clostridium botulinum'' is found ubiquitously in the soil worldwide. It is one of the most lethal substances known on earth as only 1.0 micrograms is the lethal dose for humans. Therefore the disease is zoonotic and a public health issue.

There are three ways that botulism can arise, firstly and most commonly (only one of the three that does occur in the UK) is via '''ingestion of the preformed toxin'''. Secondly, the '''spores can be ingested''' and germinate in the intestine releasing the toxin that is then absorbed, but this tends only to occur in neonates or young stock. Thirdly, the bacteria can enter the body '''through a wound''' and then proliferate again, once inside the body. The last two types of infection are rare and neither occurs in the UK. In the UK, infection usually arises when animals e.g. cattle or horses have ingested big bale silage, that has been contaminated with soil or carcasses. Carnivores can get infected by consuming rotting carcasses.

There are three ways that botulism can arise, firstly and most commonly (only one of the three that does occur in the UK) is via '''ingestion of the preformed toxin'''. Secondly, the '''spores can be ingested''' and germinate in the intestine releasing the toxin that is then absorbed, but this tends only to occur in neonates or young stock. Thirdly, the bacteria can enter the body '''through a wound''' and then proliferate again, once inside the body. The last two types of infection are rare and neither occurs in the UK. In the UK, infection usually arises when animals e.g. cattle or horses have ingested big bale silage, that has been contaminated with soil or carcasses. Carnivores can get infected by consuming rotting carcasses.

== Signalment ==

== Signalment ==

Any animal of any age, sex or breed can contract this disease. In the UK, access to big bale silage is the main cause of the disease, hence cattle and horses are most likely to develop the disease in this country.

Any animal of any age, sex or breed can contract this disease. In the UK, access to big bale silage is the main cause of the disease, hence cattle and horses are most likely to develop the disease in this country. However the incidence is quite low in these species.

 

Type C ''C. botulinum'' causes a very high incidence of disease in wild waterfowl, with thousands of birds dying each year in outbreaks in the USA and Canada.

== Clinical Signs ==

== Clinical Signs ==

Another presentation is with incoordination and knuckling followed by flacid paralysis and recumbency. Paralysis of respiratory muscles leads to death.

Another presentation is with incoordination and knuckling followed by flacid paralysis and recumbency. Paralysis of respiratory muscles leads to death.

Birds present with flacid paralysis of legs and wings.

Birds present with flaccid paralysis of legs, wings and neck. In waterfowl, neck paralysis can lead to drowning.

== Diagnosis ==

== Diagnosis ==

Management of the recumbent animal, plus fluid therapy and nutrition can be undertaken if considered economically viable. Most livestock and horses that contract the disease are destroyed on humane grounds.

Management of the recumbent animal, plus fluid therapy and nutrition can be undertaken if considered economically viable. Most livestock and horses that contract the disease are destroyed on humane grounds.

== References ==

== References ==

Rycroft, A (2007) '''Principles of Microbiology Part I; Fundamentals of Veterinary Microbiology, '''''Royal Veterinary College.'''''

Rycroft, A (2007) '''Principles of Microbiology Part I; Fundamentals of Veterinary Microbiology, '''''Royal Veterinary College.'''''

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