How Much Ragwort Is Toxic to Horses?

While it may appear attractive initially, ragwort can be one of the most toxic plants for horses. As an owner, rider, or stable manager, this means you need to be able to identify it to prevent ragwort poisoning in horses and keep them safe, happy and healthy.

What is Ragwort?

Ragwort, or Sececio jacobaea, is a common weed that grows on roadsides, embankments, and vacant land. In addition to its formal name, it has a number of colloquial names, including golden ragwort, St James wort, the tansy ragwort, and the stagger wort. 

Despite being rather pretty, it’s considered a highly invasive weed throughout many parts of the world and has a reputation for being poisonous to livestock and animals alike.

Fortunately, while most horses will avoid eating ragwort if there is other grazing available, accidents do happen, and horses can ingest it if there is nothing else to eat or if parts of the plant have dried out and become less bitter. While ragwort’s taste may improve when cut or dried, it can still be harmful. 

What Are The Dangers Of Ragwort To Horses? 

Ragwort is one of the most toxic plants for horses due to its concentration of compounds called pyrrolizidine alkaloids. The plant contains a number of these alkaloids, including senecionine, jacobine and eruifoline. These compounds cause a syndrome called pyrrolizidine alkaloid toxicity in horses and other livestock. 

Because of this toxicity, ragwort poisoning in horses can lead to liver failure, especially when animals eat the plant consistently for prolonged periods of time. Aside from being poisonous, the risk of ragwort lies in its delayed toxicity symptoms. Signs of pyrrolizidine alkaloid toxicity can take a while to show themselves. By the time they do, a horse’s liver may be irreversibly damaged, which may, unfortunately, be fatal.

How Much Ragwort is Harmful to Horses?

When it comes to how much ragwort is poisonous to horses, the answer is simple—any amount can be dangerous. Animals who ingest even small amounts of this weed over a period of time can suffer from severe liver damage. 

This is true for the common ragwort (Senecio jacobaea) and other types of ragwort, such as the Oxford ragwort and the marsh ragwort. Due to its potent toxicity, even in the smallest doses, proactive management is essential for protecting your horses. 

How to Identify and Manage Ragwort

Ragwort can be a perennial or annual herbaceous plant that produces attractive, daisy-like yellow blooms during its flowering period. The plants have rosettes of green leaves that may appear ruffled towards the base of the stem. Different members of the Senecio genus may have slight appearance variations, but they all look relatively similar.

In the UK, ragwort seedlings typically sprout between autumn and summer. They are often spotted once their leaves reach a length of around 10-15mm, although many stable owners and managers miss them until they start producing rosettes of spade-shaped leaves, which are notched towards the top ends. The plant’s yellow flowers usually bloom between June and the end of October. 

Ragwort produces prolific, flat-topped flower clusters that ripen into thousands of fluffy seed heads from July to September. The adult plants can reach heights between 30cm and 100cm and are deeply rooted, making them harder to remove.

Symptoms of Ragwort Poisoning in Horses

Ragwort poisoning in horses can produce a range of symptoms. If you notice depression, lethargy and aggression in your horses, reach out to your vet immediately for guidance. 

Other symptoms of ragwort poisoning in horses may be jaundice and a yellow tinge to the eyes and gums, weight loss and diarrhoea, signs of abdominal pain, and neurological issues like constant circling, seizures, head pressing, and a loss of balance and coordination.

Tips for Managing Ragwort 

To alleviate the dangers of ragwort to horses, use our expert tips: 

Regular Inspections

The first step to eradicating ragwort from your pastures is to inspect your fields for the plants regularly. Inspections must be performed consistently, as ragwort plants can easily pop up without your noticing and jeopardise your horses’ wellbeing. 

It’s important to be able to recognise the plants as seedlings and adults to ensure you remove them all.

Pasture Management 

If you notice any ragwort plants during your inspection, remove them as soon as possible. The most effective way to do so is before they produce seeds, which will help to limit their spread. You will need to dig up the plants by their roots during removal so they don’t regrow. It’s also recommended you use proper tools and wear protective gloves to avoid coming into contact with the toxins yourself. 

Once you’ve dug up all the ragwort plants you find, it’s vital to remove them from your pastures so your horses cannot access them. 

Seasonal Ragwort Management

Ragwort plants begin to germinate in the spring, adding another potential summer problem for horses to the list. To avoid any issues, begin your field inspections around this time, taking care to remove young plants before they can establish their root systems and start flowering in summer. It’s also a good idea to assess your pastures in autumn to remove any newly germinated plants from dropped seeds and plants you may have missed. 

Some ragwort plants may even survive winter, so ensure you check your fields during the cold months as well to keep them clear of these toxic plants for horses.

Keep Your Surroundings Free Of Toxic Plants For Horses

The dangers of ragwort to horses are serious, and any amount of this common weed can lead to serious symptoms and irreversible liver damage. But, by following the tips in our guide, you can become proactive in managing this weed and keep your horses safe from harm.