This page analyses and quotes an outrageous article published by the British horse Society in their Newsletter in March/April 2015 One of the most important things about making claims in a scientific manner is that you have evidence to support them and that the evidence is accurate. This is not a principle that the British Horse Society seems to follow in any way at all.
This needs to be explained carefully so we will start by explaining what should happen when a vet encounters a case similar to this one.
1. The symptoms indicate liver failure.
2. This has multiple causes. Ragwort type damage, which has other causes as well,is only one and research shows that it only occurs in a minority of cases.
3. If this were suspected then a test would need to be done, but because of the other causes this is not a test that proves anything. It is only indicative that certain
types of toxins are involved.
To explain this in a little more detail. The symptoms are just those of liver damage and without further examination and testing you cannot say that a horse that has signs of liver damage has ragwort poisoning just because of liver damage symptoms. There is a test which can show the symptoms of ragwort poisoning. It requires a sample to be examined under a microscope but this is not definitive since toxins that commonly grown in mouldy feed produce the same effect at the atomic level by affecting DNA molecules. This of course then causes the same microscopic signs. See Ragwort there is no test which can confirm it 100% In a survey, where this inaccurate sign was looked for, only 8% (1) of the samples could possibly have been ragwort poisoning ( or other causes like mouldy feed) Therefore, the British Horse Society were misleading their members when they wrote this highly emotive article in their members newsletter.
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. I phoned a friend to discuss symptoms, and the general consensus was one of three things - stroke, anaphylactic shock or something none of us had seen before." She was very disorientated (Ruth later found out she was blind), twitching when touching anything (like she had bumped into it) and her head would then twitch, she was i clammy and could hardly stand or walk. Ruth rugged her up in an outdoor rug and gave her flute in liquid while she waited for the vet. A bed was made for her in the stable and she changed to a cooler rug when she began sweating up The horse then lost control of her limbs. almost crushing Ruth as she fell over. ( When the vet arrived. un-rugged her and told Ruth it was liver failure due to Ragwort poisoning. Ruth was asked if she knew what that meant. "I was told I didn't have to hold her if I didn't want to. but l did. whispered in her ear while the vet injected her and she fell to the floor with the help of three of us." A sad end indeed for a beloved horse.Given all the inaccurate information which has been published it isn't impossible that a vet did turn up and make an instant diagnosis, but given the scientific evidence surely no vet should say this? Any diagnosis could not have been an definitive one because no tests had even been performed to determine any cause for the liver damage and even the test that exists does not distinguish ragwort poisoning from poisoning due to toxins in mouldy feed. The article continues to mislead people ..
Lee Hackett, Senior Executive. Welfare Department says... Unfortunately. stories like Ruth's are not so unusual. Every year we hear similar sad tales. Liver failure causes horses to suffer a horrific death, yet many people still seem to be content to allow their horses to graze in fields infested with Ragwort. No-one knows quite how many horses are affected, but anecdotally it appears that Ragwort is on the increase. In 2010 we conducted our first nationwide Ragwort survey (something we plan to repeat annually) to help us to understand the extent of Britain's Ragwort problem. Our survey showed that Ragwort is a nationwide problem and no area is immune. We identified 1,159 horses grazing in fields that had Ragwort growing in them, with the majority of these cases involving what we would class as severe Ragwort infestations. It is vital to clear your fields of Ragwort. Given that our survey can only really have scratched the surface it is terrifying to think how many horses truly are at risk of Ragwort poisoning.
This is one of the British Horse Society's typical bad surveys. They assume, falsely, that ragwort which has always been present as a common plant and with which horses have co-evolved is an automatic danger and then generate panic and hysteria by exaggeration. 1,159 horses having ragwort in their fields does not mean they are at threat of poisoning. They have been trying to claim that ragwort has been wildly increasing for years often with the most bizarre of claimed reasons. Wildflowers in the UK have declined massively since World War Two and all of the various bits of data available do not support their claim at all. The article continues to frighten as follows.
The survey also showed that many people believe a little bit of Ragwort does not really pose a threat to their horse- This delusion isn't helped by the regular sight of apparently healthy horses grazing happily in infested fields. However, Ragwort is a cumulative poison - each time a horse ingests even a small amount, damage is incurred by their liver.
It is the author of this site's honest opinion that it is Lee Hackett who is wrong. The evidence simply does not seem to support this contention at all. The biochemical evidence seems absolutely clear. Small amounts of the toxins are regularly detoxified by a number of means, including the same one which makes normal doses of paracetamol harmless to humans but leads to large amounts causing liver damage. This site has an entire page devoted to explaining the science on this here. Ragwort is not strictly a cumulative poison
Another quote from the article is...
It is also a common misconception that horses will not eat Ragwort and will graze around it. This simply is not true. While Ragwort does have a bitter taste, some animals actually grow to like this and actively seek it out.
This is another one of those cases where something should not be said because of the evidence. This particular old wives tale seems to originate from severe animal abuse. Horses have co-evolved with many plants that contain the same toxins as ragwort. They occur in around 3% of the world's plants. Like many other animals they have evolved systems to avoid poisoning, their natural immunity through detoxification methods is one, but the other is their taste system. Animals do not just develop a taste for poisons those that did didn't pass on their genes. Animals that are abused by starvation will eat anything available in desperation, but people who want to have an excuse for their bad behaviour in mistreating their animals then use this nonsense idea of the animals developing a taste for poisons as an excuse. The author of this site has spent years studying hundreds and hundreds of documents and has not found any evidence to support the notion that animals develop a taste for this native plant common ragwort with which they co-evolved.
There is an awful lot of work to do before we can even begin to win the war against Ragwort, but we have to start somewhere.
This is exactly the point. They see it as a war and produce propaganda. The proper place to start with this is to establish whether ragwort is a problem or not. They have just assumed it is and repeated and repeated the same falsehoods without checking them.
All in all this is an example of the British Horse Society's campaigning using nonsense and scare stories to misinform over the issue. The evidence does not support their contentions.
References:
1. Surveillance focus: ragwort toxicity in horses in the UK Andy E. Durham Veterinary Record 2015 176: 620-622
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