Today I am giving my honest opinions on a page on ragwort by the Sussex Equine Hospital. I need this to post for two different comments I have seen on line. One is putting this page forth as a good example of information, which it clearly isn't and another asking about British Horse Society surveys, which are appallingly bad.
The page is an example how even vets get things wrong. It is likely that in this case it is largely inadvertent and that some of it is ignorance which is common even in equine vets and that largely the problem lies with the British Horse Society.
The article starts with a set of poor claims:-
Ragwort (also known as Senecio Jacobaea) toxicity is one of the most common causes of poisoning to horses in the UK. A recent survey by the British Horse Society showed that 20% of respondents knew of a horse that had been affected.
Firstly, no one can know properly that a horse can have ragwort poisoning without additional evidence other than just symptoms. This is because other substances can cause the same damage at an atomic level. So you cannot say how common it is! It is in some of the modern textbooks and has been known about since 1961 but many vets don't know this. You see this mistake all the time and I have had to correct them in the past. Just to explain why I am so certain about it. A colleague attended a ragwort meeting where a veterinary professor was talking and got the information about aflatoxicosis ( A kind of mould poisoning) causing identical symptoms from him. There is also this quote from a recent paper by the Animal and Plant Health Agency (APHA) in the Veterinary Journal about a rare case of pigs and ragwort.
"Acute aflatoxicosis could cause similar pathology but the clear access to ragwort plants and the knowledge that pigs on other units on the same commercial pig diet were healthy, pointed away from this potential cause."
We know there is no reliable test for ragwort poisoning. In this case it was obvious with the pigs, but in the overwhelming number of horse cases it isn't.
The second point that a survey by the British Horse Society said that 20% of respondents knew of a case. Of course the first point applies and they couldn't have known of a case but we need also to look at the survey.
The bent survey is a speciality of the British Horse Society. They are well known for running them and for repeating them. First of all there is the British Equine Veterinary Association survey which they publicised widely. As I have previously written, I attended a ragwort symposium in the Netherlands last year and their survey methods had a room full of top ragwort scientists hooting and moaning in derision.
First they designed a poor survey they didn't check how diagnoses were achieved properly. They didn't check for duplicate cases where more than 1 vet was involved etc.. As I've said there is no definitive test so how could they know.? They got a tiny number of responses just 4% and then outrageously multiplied the figures they got as if everyone had answered!
Those figures were as bent as a butcher's hook and yet the BHS publicised them. Worse people selling ragwort controls used them, illegally, in their advertising. I took these to the Advertising Standards Authority and got them taken down.
Now we come to the survey in question and wait for it this is a real corker! First of all they put an article in their newsletter, with a highly emotive article about how terrible ragwort was see the excerpt below. NOTE they provided an example of supposed ragwort poisoning. Actually they claimed a vet turned up and proclaimed it was ragwort poisoning on the spot. This may well have happened but is not what a vet should do to establish poisoning.
This is the excerpt I mention above.
"Our Welfare Department recently heard a harrowing story of Ragwort poisoning from Ruth Anderson, who kept her horse in a yard on the south coast...... One morning she found her horse, covered in mud, and looking as if she had sweated up during the night. It appeared she may have had colic or had been charging round like a mad thing (spooked over something). so we kept an eye on her," said Ruth. "Then she wouldn't eat her dinner, she had a 'mad twitch' and was pitching her head to one side. "
This of course biased the survey. It is well established that these sorts of things bias surveys and rig the results. You can read more details of the article here https://www.ragwortfacts.com/british-horse-march-april-2015.html
( You can also read about yet another survey where they had used people seeing horses near ragwort in a previous well publicised survey, which isn't necessarily a problem. It didn't stop them using it as a scare story in the press.)
The survey then started with a false and leading question asking if people knew that ragwort was "extremely poisonous" to horses. This in scientific terms isn't true. Extremely poisonous substances are thousands of times more toxic than ragwort! Of course this biased the survey yet again.
Then and this is the real corker! They asked people if they had ever heard of a case, after providing an example for them to know about in the newsletter article asking them to fill in the survey!
Of course all of these factors, biasing the survey and the impossibility of really knowing ragwort caused all the cases rendered the survey figures useless, but it didn't stop them from publicising this figure which the vets have repeated.
Then there is this comment which you see all the time but, honestly, if you look at the evidence , it isn't true,
"The effect is cumulative and symptoms may not be seen for up to a year after exposure."
First of all the biochemistry shows that the damage only occurs and therefore is only cumulative if a threshold is exceeded. The toxins can be destroyed or inactivated and there are repair mechanisms. Secondly there are TWO scientific papers describing experimental poisoning experiments where, as expected, small doses have no effect.
Then again inaccuracies.
"The poison effects 3 main body systems - the liver, the central nervous system (brain, spine and its associated nerves) and the skin."
The alkaloids in ragwort affect the liver and the other symptoms are caused by liver failure which stops the liver breaking down toxic substances that build up naturally in the body.
Then this old chestnut of a falsehood which regular readers will recognise!
" However, the Weeds Act 1959 made ragwort control a legal obligation for owners and occupiers of grazing land. "
This is of course utter nonsense. The law says no such thing. You may be ordered to control ragwort, but in the absence of a rare order there is no obligation to do anything. Maybe the vets got this off the British Horse Society too.
Finally, I'll post a piece of TV comedy as I have before. It is from the comedy Yes Prime Minister where Sir Humphrey Appleby explains how to rig an opinion survey in an exactly similar way to that which the British Horse Society does, by asking leading questions.
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