Common ragwort is a tall, beautiful yellow flowering plant that often adorns wastelands and grazing and conservation areas.
It flowers from June to November and is an essential plant for more than 30 species of pollinator, including the daisy carpenter bee and cinnabar moth, meaning it has significant benefits to conservation.
However, though its presence is celebrated in wildlife conservation areas, ragwort is less welcome on land used for grazing, as all parts of the plant are poisonous to livestock and horses. Therefore it needs managing in these areas, as veterinary surgeon Malcolm Morley, from the British Veterinary Association, explains.
Why is ragwort poisonous to horses and livestock?
“Ragwort is a poisonous weed containing toxic pyrrolizidine alkaloids, and can seriously harm grazing animals like horses, cattle, sheep and goats, if eaten,” he says.
“Whilst most animals instinctively steer clear of it, they can be tempted when food is scarce, and the plant can sometimes become inadvertently mixed with stored hay or silage.
“The effects of ragwort toxicity are not immediate; rather they gradually build up over time, eventually causing severe, irreversible damage to the liver.
“Liver failure caused by ragwort ingestion typically shows up with non-specific symptoms, such as poor health, weight loss and a general failure to thrive. In more severe cases, affected animals may exhibit heightened sensitivity to light (photosensitivity) or neurological signs like dullness, disorientation, and even collapse.
How can ragwort be controlled?
“Effective pasture management is crucial to tackling the issue, and anyone overseeing grazing land should be able to identify ragwort,” says Malcolm.
“It is a biennial plant and forms distinctive ‘crowns’ in its initial year within the pasture. Ideally, this is when the entire plant should be pulled out by the roots, to prevent it from flowering and self-seeding.
“Working with neighbouring landowners to reduce spread is vital due to the way ragwort’s seeds are carried on the wind. To prevent inadvertent consumption, it’s best not to cut pastures for hay or silage if ragwort is present. Ensuring that animal feed and forage remain free from ragwort contamination is fundamental for safeguarding livestock health.”
Is ragwort poisonous to humans?
In their Code of Practice on How to Prevent the Spread of Ragwort (2004) DEFRA states: ‘Humans may be at risk from ragwort poisoning through direct contact (e.g. hand pulling)’.
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Malcolm Morley is the Senior Vice President of the British Veterinary Association
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