"There's nothing so absurd that if you repeat it often enough, people will believe it."
So wrote William James the famed philosopher who is often regarded as the father of modern psychology.
This is an entry from the blog of vet Paul Proctor MRCVS
"Ragwort is a common weed that grows throughout the British Isles, and has always been a problem but recently it has become apparent that the weed may be getting out of control and potentially posing a real threat to the horse population."
The article is good in other respects and Mr Proctor seems to be a perfectly fine vet. However, on the basis of the FACTS, I have to disagree with that statement.
There is no evidence that Ragwort is "getting out of control". There is no evidence
that it is increasing. If anything the evidence from the government's
UK Countryside Survey is that Ragwort is decreasing. At least he has the good sense to use the words "may" and "potentially".
What there is a lot of evidence of, and the reason for this blog, is a concerted campaign of misinformation and falsehoods. These are often promoted quite innocently by people who just do not know the facts and who are unnecessarily frightened. Sometimes they are promoted by commercial companies with a product to promote. Sometimes by organisations who need to raise their profile, and who do so by putting scary stories into the media.
The story that ragwort is increasing is, in the face of the facts, absurd, but as William James said it is been repeated often enough that people will believe it.
The problem with vets believing that ragwort poisoning is common, rather than what the literature indicates, that it is rare, is that it manifests itself like any other type of liver damage that is from other causes.
There is a risk, if vets believe that ragwort poisoning is more likely than it is, that animals will suffer as a result of misdiagnoses.