Changes

Also known as:'''''Senecio jacobea'' toxicity

Also known as:'''''Senecio jacobea'' toxicity

[[Image:Ragwort.JPG|thumb|right|250px|<p>'''Ragwort''']]

[[Image:Ragwort.JPG|thumb|right|250px|<p>'''Ragwort''']]

==Introduction==

==Introduction==

'''Ragwort''' (''Senecio jacobea'') is part of the daisy family, a flowering plant with completely yellow flowerheads. It commonly grows on wasteland and grazing pastures.  

'''Ragwort''' (''Senecio jacobea'') is part of the daisy family, a flowering plant with completely yellow flowerheads. It commonly grows on wasteland and grazing pastures.  

It is poisonous to livestock with Horses and cattle being more susceptible than sheep. When ingested over long periods of time it causes hepatotoxicity which in the severe form is invariably fatal. Exposure to the toxin is usually via ingestion of contaminated hay or silage as the animal will avoid it in the fresh form.  

It is poisonous to livestock with horses and cattle being more susceptible than sheep. When ingested over long periods of time it causes hepatotoxicity which in the severe form is invariably fatal. Exposure to the toxin is usually via ingestion of contaminated hay or silage as the animal will avoid it in the fresh form.  

The toxin is a '''pyrrolizidine alkaloid''' which is converted in the body to the toxic intermediate '''pyrroles''' and their esters which cause intitial and continued damage to hepatocytes. They have an anti-mitotic effect whilst allowing continued synthesis within the cell and its nucleus resulting in a marked increase in the size of the hepatocytes. The attempted repair by fibrosis aids the shunting from the portal triads to the central vein, thereby bypassing the hepatocytes and resulting in the clinical signs associated with liver failure.

The toxin is a '''pyrrolizidine alkaloid''' which is converted in the body to the toxic intermediate '''pyrroles''' and their esters which cause intitial and continued damage to hepatocytes. They have an anti-mitotic effect whilst allowing continued synthesis within the cell and its nucleus resulting in a marked increase in the size of the hepatocytes. The attempted repair by fibrosis aids the shunting from the portal triads to the central vein, thereby bypassing the hepatocytes and resulting in the clinical signs associated with liver failure.

*Rose, R. J. and Hodgson, D. R. (2000) '''Manual of Equine Practice''' (Second Edition) Sauders.

*Rose, R. J. and Hodgson, D. R. (2000) '''Manual of Equine Practice''' (Second Edition) Sauders.

[[Category:Hepatotoxicity, Chronic]]

[[Category:Hepatotoxicity, Chronic]]

[[Category:Liver Diseases - Horse]][[Category:Liver Diseases - Sheep]][[Category:Liver Diseases - Cattle]]

[[Category:Liver Diseases - Horse]][[Category:Liver Diseases - Sheep]][[Category:Liver Diseases - Cattle]]

[[Category:Neurological Diseases - Horse]][[Category:Neurological Diseases - Sheep]][[Category:Neurological Diseases - Cattle]]

[[Category:Neurological Diseases - Horse]][[Category:Neurological Diseases - Sheep]][[Category:Neurological Diseases - Cattle]]

[[Category:Expert_Review]]

[[Category:Expert_Review - Horse]][[Category:Expert Review - Farm Animal]]

[[Category:Toxicology]]

[[Category:Toxicology]]