Changes

Jump to navigation Jump to search
1,101 bytes removed ,  20:48, 24 August 2010
Line 8: Line 8:  
In healthy animals, there is a balance between multiplication of ''Clostridium perfringens'' and its passage in the faeces. This ensures that infection is maintained at a low level.  However, ''C. perfringens'' is saccharolytic and is therefore able to multiply rapidly when large quantities of fermentable carbohydrate are introduced to the anaerobic conditions of the abomasum and small intestine, leading to build-up of exotoxin. Gut statis, for example due to insufficient dietray fibre or a high gastrointestinal parasite burden, can also contribute to the accumulation of toxins.  
 
In healthy animals, there is a balance between multiplication of ''Clostridium perfringens'' and its passage in the faeces. This ensures that infection is maintained at a low level.  However, ''C. perfringens'' is saccharolytic and is therefore able to multiply rapidly when large quantities of fermentable carbohydrate are introduced to the anaerobic conditions of the abomasum and small intestine, leading to build-up of exotoxin. Gut statis, for example due to insufficient dietray fibre or a high gastrointestinal parasite burden, can also contribute to the accumulation of toxins.  
   −
Enterotoxaemia due to ''Clostridium  perfringens''  type D causes sudden death in sheep of any age, particularly well-grown lambs of between 4 and 10 weeks of age and fattening lambs of 6 months to 1 year old<sup>lewis</sup>. Rams are also susceptible when they are subjected to an incraesed plane of nutrition prior to mating. The condition is associated with a change in diet, for example to include lush grass or high proportions of concentrate. This leads to rapid multiplication of the bacterium and excessive production of its &epsilon; toxin. &epsilon; toxin causes vascular damage, particularly of the capillaries in the brain<sup>merck</sup>. The incidence of pulpy kidney declined over the past 25 years or so, due to the widespread use of clostridial vaccines<sup>3</sup>, but the condition is now becoming a problem again as complacency reduces the use of vaccination. At its most extreme, pulpy kidney can cause losses of 10-15% of the lamb crop. The disease can also occur in cattle, but this is rare<sup>ivis</sup>.
+
Enterotoxaemia due to ''Clostridium  perfringens''  type D causes sudden death in sheep of any age, particularly well-grown lambs of between 4 and 10 weeks of age and fattening lambs of 6 months to 1 year old<sup>lewis</sup>. Rams are also susceptible when they are subjected to an incraesed plane of nutrition prior to mating. The condition is associated with a change in diet, for example to include lush grass or high proportions of concentrate. This leads to rapid multiplication of the bacterium and excessive production of its &epsilon; toxin. &epsilon; toxin causes loss of epithelial integrity, leading to increased capiliary permeability and oedema formation in many tissues, particularly the brain<sup>merck, ivis</sup>. The incidence of pulpy kidney declined over the past 25 years or so, due to the widespread use of clostridial vaccines<sup>sargison</sup>, but the condition is now becoming a problem again as complacency reduces the use of vaccination. At its most extreme, pulpy kidney can cause losses of 10-15% of the lamb crop. The disease can also occur in cattle, but this is rare<sup>ivis</sup>.
 
  −
 
  −
 
  −
 
  −
 
  −
ivis: perfringens type D causes enterotoxemia in small ruminants of all ages; [1,10] disease in cattle appears to be very rare [27]. Clostridium perfringens  type D is not considered to be a common inhabitant of the gastrointestinal tract of normal ruminants, although it can be carried sporadically by healthy animals [10]. As for type C enterotoxemia, passage of soluble carbohydrates or protein into the small intestine is thought to induce rapid replication and elaboration of epsilon toxin from this organism [24]. Unlike beta toxin, however, epsilon toxin is activated by intestinal and pancreatic proteases [1]. Once absorbed into the bloodstream, epsilon toxin causes loss of endothelial integrity, increased capillary permeability, and edema formation in multiple tissues [28].
  −
 
  −
Type D enterotoxemia in sheep is typically a peracute illness, with many cases simply being found dead. If a live ovine case is detected, neurologic signs predominate. Lethargy and ataxia are evident early on, with collapse, hyperesthesia, lateral recumbency, convulsive paddling, and opisthotonus following within hours. Diarrhea is inconsistently seen. Glucosuria is frequently present [29].
      
==Signalment==
 
==Signalment==
6,502

edits

Navigation menu