Has anyone had any experience with Ragwort poisoning?

Question

Unfortunately yes, I have only had her less than six months and my vet says it was probably in her systems for quite a while. I am devastated.

Answer 1

This is a long answer, please bear with me.
The toxic effects of ragwort are due to pyrrolizidine alkaloids (PAs) which are present in all parts of the plant, including the seeds. Although PAs also occur in other plants, common ragwort presents the greatest risk for horses because of its widespread distribution in poorly maintained pasture and in grassland used for hay production.

The PAs are rapidly absorbed from the gastro-intestinal tract. They pass to the liver where they are broken down to produce toxic compounds called pyrroles. These act on the DNA of hepatocytes (liver cells) and prevent cell division. Consequently, the hepatocytes are unable to divide and become large cells called megalocytes. When the megalocytes die they release toxins which may be taken up by neighbouring cells. The dead cells are replaced by fibrosis, which may itself cause further damage to other cells. Thus the damage to the liver is progressive.

The liver is able to maintain normal function until at least two-thirds of its tissue has been destroyed. So the ragwort toxins are able to wreak havoc in the liver without being detected. By the time the horse shows signs of liver failure the damage to the liver is so extensive that treatment is not possible.

Because the liver has many functions, the signs that are seen when it fails vary. The first indications may be weight loss, photosensitive dermatitis (inflammation affecting only the non-pigmented skin), lethargy or change in behaviour. As the condition deteriorates, the behavioural abnormalities get worse, the horse starts to wander aimlessly and stagger about. It may stand with its head pressed against the wall, become blind and have difficulty breathing. The signs can develop so quickly that the cause of death may be wrongly attributed to something else like "heart attack", "stroke" or colic. In some cases the horse may be found dead without warning.

Currently there are no simple tests available to specifically detect ragwort poisoning. There are tests that can detect damage to the liver - in particular looking at liver enzymes in the blood. Liver function can be assessed by measuring bile acids. If the liver function is impaired the levels of bile acids in the blood increase. Neither enzymes nor bile acids are specific for ragwort.

It can also be difficult to confirm that ragwort is the cause of the liver disease because the effects of the toxins are seen long after the plant has been ingested. There may be no sign of ragwort in the diet of the horse when signs are seen. A diagnosis of ragwort poisoning may have to rely on finding typical microscopic changes in the liver.

In the absence of an effective treatment for ragwort poisoning it is all the more important to prevent horses having access to the plant either at pasture or in contaminated hay. Preventing ingestion of ragwort is the only way to prevent ragwort poisoning.

Ragwort can be difficult to identify when it is dry in hay. Feed samples can be analysed for PA content. This is time consuming, relatively expensive, and the reliability of the result depends upon the accuracy of the sample.

Treating liver damage in a horse with ragwort poisoning is the only option, and needs to addressed to prevent further associated problems. Often diagnosis is complicated and may require blood analysis to check liver enzymes and metabolite levels.

A specific blood test for liver damage is called the 'BSP clearance test' and is a more reliable indicator of liver disease than the liver enzyme test, which can give misleading information about the true severity of the hepatitis.

Once liver disease is diagnosed, a needle biopsy of the liver is often vital to establish the likely cause.

This involves a long biopsy needle being introduced through the right side of the chest and is undertaken with some caution, especially if the horse already has coagulation (clotting) problems or might have abscesses, which could be accidentally burst by the needle.

Ultrasound pictures will help guide the needle. A liver biopsy is the best diagnostic tool available and owners should not be resistant if a vet suggests one. It is not very invasive and not too painful.

Standard treatment of liver failure symptoms are well worth attempting in many cases because the liver usually has a remarkable ability to regenerate and replace damaged tissue.

Glucose may be given by drip to provide energy, and mineral oil by mouth to reduce the uptake of toxins from the gut. Oral doses of antibiotics, such as neomycin or lactulose, can also be used to reducegut toxin and ammonia production.

Horses which are behaviourally disturbed as a result of liver damage can be sedated if necessary. The best course of action for photosensitive horses is to apply sun block to affected areas and keep them out of bright sunlight.

Overall, liver failure cases that develop rapidly are more likely to respond to treatment and cases that have a slow onset usually indicate a more serious hepatitis. When symptoms are severe, there is real danger that treatment will be unsuccessful...

Answer 2

No, thank goodness. The stables where I used to keep my horses were very strict about its removal and destruction. I suspect that your horse managed to eat it when it was cut, or baled with hay as they usually avoid eating a live plant due to the nasty bitter taste it gives off - it generally only becomes palatable when it is dried. One of the worse effects is possible liver damage.

The only thing I can say is that you have to go by what your vet says about the ongoing therapy that will be needed. The horse's liver is able to recover to a certain extent, which hopefully in your horse's situation will be the case. The long term prognosis is difficult to say for work, but hopefully given the prompt treatment and care your horse will still have a quality of life, even a return to work.

Your vet will probably give blood tests regularly and also advise on diet and other possible treatments.

Don't give up hope and good luck.

Answer 3

No, thank god......dig or pull it up and burn it.....we cut 8 acres last summer, baled it and burnt the bales, that was ok, but it will not be dead so we will spray for ragwort in march. I feel realy sorry for you if you have a horse with poisoning. Did it come from the hay you are using?

Answer 4

Yes, sadly I have had some experience with it, but the pony I had with it was very advanced and didn't make it. Hopefully you have caught it in time to do something about it.
Good luck

Answer 5

I help my friend get rid of it from a verge that borders the field her horse's are in but it always grows back-nothing seems to kill the plant!

Answer 6

Sorry no, I am paranoid about the stuff and dig it up whenever I see it in our fields or the lanes around them. We always burn it.
Luckily the people who had the fields before us were the same so we don't get much.

Answer 7

No It's only horses and cows that get it

Answer 8

no:D