Ragwort (Senecio jacobaeo), is found throughout the British Isles and has toxic properties that equine lovers should know about.
The weed thrives on wasteland and can spread to horse pastures.
The plant has a bitter taste which equines will tend to avoid, but will lose this taste when the plant starts to wilt whilst retaining its toxic properties.
The toxic compounds pyrrolizidine alkaloids present in ragwort are absorbed through the gut wall into the bloodstream and then passed through the liver. The liver is incapable of removing the alkaloids, or rendering them harmless, and as a result the liver cells (hepatocytes) are damaged beyond repair.
This can result in liver failure (or hepatic failure) which normally occurs when more than 70 percent of the liver has been damaged.
The signs of ragwort poisoning will depend on how much and how long the equine has been exposed to the alkaloids. Often signs will manifest once a significant amount of damage has already occurred.
Blood tests can identify reduced liver function, in some cases, an ultrasound scan and a liver biopsy may be required.
Unfortunately once clinical signs of liver failure such as weight loss, abdominal pain or colic, diarrhoea, jaundice, lethargy, loss of coordination, continuous circling, aimless walking, aggressiveness or seizures become evident there is no effective treatment. Treatment is aimed at supporting the functions of the liver and keeping the horse comfortable, in severe cases euthanasia is the only viable option.
HAPPA recommend removing all ragwort from equine pastures by pulling up the plant or spraying with an appropriate herbicide. When handling ragwort it is very strongly advised that you wear protective equipment such as gloves, long sleeves and a face mask due to the risk of absorbing toxins through your skin.
For more information visit bhs.org.uk