(Senecio Jacobaea and contains toxic compounds Pyrrolizidine Alkalodis)
You have seen this plant, on the roadsides but worst of all in your horses paddock, that’s right Common Ragwort. It’s a prevalent weed growing throughout the UK, it’s recognised by it’s yellow flowers.
It’s a pretty plant and a great plant for pollinators, but it does have poisonous properties to which horses are susceptible. Many of us that have pulled this yellow terror, we know what a joy of seeing it burn to kill this plants seeds. But pulling this by hand has consequences of it’s own unless you wear gloves. Apparently the poison can transmit into human skin.
I’ve seen this common site of horses grazing in paddocks with Ragwort growing all around. This plant has a bitter taste, so while it’s growing it’s not a issue but as soon as it’s cut and dry this is where the problem starts, your horse would not eat it normally as it’s not a choice of food. Starvation areas for horses is where it is like to grow best.
Ragwort loses it’s bitter taste as it’s wilts so becomes more tasty for horses, but unfortunately it retains its toxic properties. So when it’s dried and made into Hay or Haylage horses can not tell the difference, especially if the forage is made early like this spring, the plants are hard to spot as they have not grown tall and flowered. So wherever you buy your forage from no one can guarantee their forage is free from this flower.
So why is this bad for your horse? Well it’s a accumulative toxin by ingesting small low levels so the damage is done over time, your horse may not show any signs of Ragwort poisoning. There is often no warning signs as the toxin targets the liver hence your horse may have quite a severe liver damage but appear healthy.
I’ve had to ask a vet for the clinical signs of liver damage.
• Weight loss
• Abdominal pain or colic
• Head pressing (often against a wall)
• Continuous circling
• Loss of coordination
• Aimless walking
Don’t let the signs scare you? The above are worst case but the diagnosis of liver failure is based on the history of the horse, blood tests and ultrasound scans of the liver and possibly a biopsy may be required.
So how does the toxin damage the liver?
The cells of the liver lose the capability to regenerate and unfortunately they die, they are replaced by fibrous tissue. The more cells that die the more fibrous tissue covers the liver so the end result is the liver shrinks. So over time months or years as the cells die there is not enough healthy liver to function. (Vet speak!! Hepatic Failure) or for us mortals Liver failure normally occurs when more than 70% has been damaged.
There is no treatment or cure available to undo the damage.