In 2002 BEVA contacted all its members in relation to the impact of ragwort poisoning. Out of all its members 4% responded to say that they had seen, on average, 3 ‘suspected’ (note – not ‘confirmed’) cases of ragwort poisoning. BEVA then took the unscientific step of simply multiplying the number of suspected cases to cover their full membership, producing a total of 6,500. At no point did it appear to occur to anyone conducting the survey that 96% failed to respond because they had no cases to report. There is also a possibility of neighbouring vets reporting the same incident, leading to it being recorded twice. Indeed, I have heard of equestrian vets who have practiced for 30 years and have never encountered a single case of suspected ragwort poisoning. However, since its publication, the BEVA figure has developed an unquestionable life of its own - it is continuously quoted whenever the topic of ragwort rears its head.
It is also interesting to learn that, according to the latest research, for it to be fatal, an animal would have to eat a vast amount of it – estimates are a minimum of 5% of bodyweight (and possibly a lot higher) for horses and cattle and a minimum of 125% of bodyweight for goats. Indeed, I have heard of instances of pregnant ewes making straight for it, probably instinctively knowing that the toxins will fight against parasites that could be harmful to the unborn lambs.
A survey in the Netherlands, where Post Mortem examinations are performed to ascertain causes of death, reported that the country has had no cases relating to ragwort poisoning at all since 2007.
In 2005 the Irish Minister for Agriculture and Food stated that cases of ragwort poisoning in the country were deemed to be so low as to not constitute a problem worthy of investigation.
Both these examples would support MAFF's 1990 conclusion.
Another belief is that the plant is so toxic that the poison can be absorbed through the skin of anyone pulling it. However, there appears to be no scientific evidence of this being true. Bees regularly take pollen and nectar from ragwort, but there has never been a claim of the resultant honey being poisonous. Personally, I would always wear gloves because of the noxious smell that would impregnate the hands. However, it is worth bearing in mind that the toxins in ragwort can cause an allergic reaction in some people (which also applies to many other plants, especially of the daisy family).
Another claim is that it can spread at an alarming rate, the seeds being carried vast distances on the wind. However, the latest research indicates that 60% of seeds fall at the base of the plant, with lessening volumes being carried further away. However, it is only the lighter seeds – those less likely to be viable – that are dispersed at any distance. In fact, botanical surveys have indicated that the plant's distribution has not changed significantly since the 1960s.
It is estimated to support around 120 (and probably higher) different species of invertebrate – more than any other wildflower. Of these, 30 species, some rare or scarce, rely entirely upon it for their existence, including 7 beetles, 12 flies, 7 micro moths and 1 macro moth (the black and yellow-banded cinnabar moth caterpillar that turns the toxin to its own advantage to deter predators). Any eradication of the plant would therefore prove to be fatal for these populations. It is ranked as one of the most visited plants by butterflies, bees and insects – a major source of nectar for at least 30 species of solitary bee, 18 species of solitary wasp and 40 species of nocturnal moth.
The only places where I have seen it as a real problem are all sites that have been heavily over-grazed and that clearly requires a radically different management approach.