Saturday, 21 July 2012

David Fursdon's unnecessary worry

The  prime reason I blog about this issue is because all the unnecessary fuss about ragwort offends my sense of reason. I have been studying this plant and the overreaction for many years. I know and understand the science and how to apply good critical thinking skills to data. For anyone who understands the scientific method and lives a rational life the nonsense about ragwort sticks out like a sore thumb. In fact it is very obvious to me that the fuss about ragwort is unnecessary and as I blogged about before in reference to the fuss  they made it all up.

That is , as I said, quite a charge to make, but it is supported by the evidence and when the Advertising Standards Authority, who are independent and look at the evidence, judged the things that I blog about they agreed with me.

The topic for today are the comments made by David Fursdon on twitter. He shows a flower of ragwort and says the following :-

Do you think the staff in St James Park think it's a flower? Luckily cavalry horses are in barracks.
A little googling shows a bit about David Fursdon's background and it is perhaps understandable why he is concerned. There has been a constant barrage of misinformation about ragwort. There have been lurid stories and many websites including official ones contain incorrect information.

As someone else has pointed out ragwort is of course a flower, but I think we can take it that in this context and working within Twitter's character limit he meant a cultivated flower. Here is another point, the alkaloids in ragwort occur in many plants. 3% of all flowering plants in fact and more googleing shows that there are many places in London where plants like Brachyglottis grayii are growing. These used to be in the genus Senecio like ragwort used to be, and are commonly planted ornamental plants, and yes they do contain the same alkaloids. In fact there are some in a park a stones throw from where I am sitting. They pose no risk.

David Fursdon goes on to say:-

It is just in front of Buckingham palace but down below. Not sure how little a horse has to eat to do it damage.

This page on ragwort toxicity will provide the detail. In fact for a horse it is 5% to 25% of body weight and we know from the biochemistry that small doses will have no effect. There are many things which can prevent the alkaloids from harming the liver and there are actually repair mechanisms which can completely undo the harm.

We know very very clearly from the biochemistry, evolution and genetics of taste, that animals are beautifully constructed to avoid eating poisons. Horses are no exception. The only risk comes from hay or animals cruelly deprived of food and starved into eating anything.

There  is as I said a  barrage of lurid nonsense that we regularly see in the horsey press, like this stuff in Horse and Hound or this bunkum from Your Horse Magazine, However, the international data and scientific literature all show that ragwort poisoning is rare. For example, at Liverpool University's veterinary hospital between in the five years between s 2006 and 2010 there was not one single recorded case of ragwort poisoning.

And lest the usual argument be made about isn't it better to be safe and not let any danger be present, I should point this out. David Fursdon's picture contains another plant that the available statistics seem to show is associated with the deaths of  far more horses. Equine Grass Sickness, a malady which research suggests is a form of botulism and which is associated with grass fed horses appears far commoner than ragwort poisoning. This may seem bizarre to some , but this is only because of the hyperbole and nonsense in circulation with regards to ragwort.

As I frequently mention good information on ragwort based on scientific data is available from these websites.

Ragwort Facts
Ragwort Myths and Facts

The second of these sites is written by someone who initially believed the nonsense until she studied the science. She then gathered an international cast of experts to help her write the site.

Ragwort Hysteria latest entries

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