This website is the English version of our Dutch Ragwort website.
Recently, Ragwort has received quite a bit of media coverage. Many facts are presented, but also many myths. It is, for instance, a fact that species of Ragwort are poisonous to mammals, but it is a myth that an animal dies if it ingests only a mouthful. It is also a fact that Ragwort is poisonous to humans, but a myth that it is a serious health hazard to people. Furthermore, it is a fact that Ragwort is currently more common in the Netherlands than 30 years ago, but a myth that this species is an extremely efficient wind disperser.
Although Ragworts can be a significant nuisance to horse keepers, these species are a very important source of nectar and pollen. About 150 species of insects, such as bees, flies and butterflies, visit the plant. Therefore, even it were possible, eradicating the plant is not a desirable option. We will have to find other ways to protect our livestock. There are no easy solutions to the Ragwort problem, but that doesn’t mean that there is nothing we can do.
The aim of this website is to distinguish facts from myths by using a scientific approach based on research and advice from biologists, toxicologists, and other experts. In this way, we want to determine the nature and scale of the problem that Ragwort presents to our horses and other livestock. In this way, I would like to contribute to a solution of the Ragwort problem; as a horse lover AND as a Ragwort enthusiast.
Frequently Asked Questions.
Q: Is it true that horses usually do not eat fresh Ragwort?
A: Yes, that is right. Only in exceptional circumstances or when there is a food shortage, horses will eat fresh Ragwort. Horses, however, don't recognize dried Ragwort plants as poisonous and contaminated hay may cause Ragwort poisoning. More info
Q: Will my horse get ill when it occasionally eats a mouthful of ragwort?
A; No, incidentally ingesting small amounts of Ragwort will not result in illness. If, however, horses eat several kilograms of Ragwort a day or small amounts for extended periods, this may lead to irreparable liver damage. More info
Q: Do the toxins in Ragworts accumulate in a horse’s body?
A: No. The toxins (pyrrolizidine alkaloids) are excreted within 24-48 hours. If an animal consumes pyrrolidizine alkaloids regularly though, liver damage will accumulate and the animal will show signs of illness. More info
Q: Is it true there are several hundreds of victims each year?
A: The exact number of victims of Ragwort poisoning is unknown. The symptoms of Ragwort poisoning cannot be distinguished from other liver disorders and poisoning can only be confirmed by means of a post-mortem liver exam. These exams are, however, not common practice, and reliable data on the number of victims are therefore not available. There could be more than hundreds of victims, but there could also be much fewer. More info
Q: Will touching a Ragwort plant result in alkaloid poisoning?
A: No. Ragwort poisoning takes place in the digestive system. In the plant, pyrrolidizine alkaloids are stored in their non-toxic form. Only if these substances end up in the digestive system, they will be converted into their toxic form. There is no scientific evidence that skin contact leads to the conversion of non-toxic alkaloids into their toxic form. Some people experience an allergic reaction after skin contact (compositae dermatitis), but this response is cause by sesquiterpene lactones rather than pyrrolizidine alkaloids. These sesquiterpene lactones are common chemical compounds of members of the Sunflower family. More info
Q: Are all Ragwort species poisonous?
A: Yes, all Dutch Ragworts contain pyrrolizidine alkaloids. These are also found in Comfrey and Butterbur.
Q: Why is Ragwort fairly common in horse pastures?
A: Ragwort needs a bare spot to germinate. Horses easily churn up the ground when running, and graze the grass very short, thereby easily creating open spots suitable for seed germination. More info
Q: Why is Ragwort nowadays more common in the Netherlands than before?
A: Ragworts are presumably more common in the Netherlands and neighboring countries than 30 years ago, because the number of suitable habitats has increased due to large-scale renewal of infrastructure, building activities, and efforts to give agricultural land back to nature. In addition, Ragwort seeds have been used to enrich roadsides. There is no evidence that Ragworts have a different habitat preference or better dispersal capabilities than in the days when this species was much less common in the Netherlands. More info
Q: How can I recognize Ragwort?
A: Ragwort is a biennial. In the first it only has leaves organized in a rosettes. These can be found throughout most parts of the year. Ragwort usually flowers in the second year (June till October). After the plant has produced seeds, it dies. The leaves of Ragwort are pinnately lobed. Flowerheads often occur in clusters called corymbs. They are yellow with ray and disk flowers. Click here for pictures of Ragwort and other Ragwort species.
Q: I have Ragwort plants growing in my horse's field, what can I do?
A: Ragwort is difficult to eradicate and most methods to remove the plants, such as pulling by hand, mowing, and using herbicides, may have increase rather than decrease the number of Ragwort plants at a given site. The best way is probably to prevent ragwort from establishing in a pasture. Good pasture management is therefore of utmost importance. More info
Q: Is it true that the toxin in Ragworts can poison a whole bale of hay?
A: No. The toxins remain in the plant and don't 'contaminate' the rest of the hay. It is advisable though not to use the rest of the bale for consumption, because undetected parts of the plant may have remained in the hay and can potentially lead to Ragwort poisoning.
Q: There's so much contradicting information about ragwort on the internet. How do I know who is right?
A: Everything that is published on the web should be regarded with skepticism, because everybody can create a website these days and everybody claims to be an expert. It is therefore important to check if statements are supported by the results of professional scientific studies published in peer-reviewed journals. If a statement on a website is not accompanied by a reference to such a scientific paper, it is safest to assume that the statement reflects the views of the author rather than a scientific fact. Otherwise the author would have bothered to refer the reader to where the evidence supporting the statement can be found.