Ragwort when it is fresh and growing has a very bitter taste. This means that horse’s are unlikely to eat it unless limited grazing is available. It tends to grow tall and when it is knocked down and becomes dried, it is more palatable to equines. This is similar when it is made into hay.
The toxic dose of the poison contained in ragwort is cumulative. This means that even if it is eaten over time the effects of the poison will continue to do damage to the horse or pony. The toxic dose is between 1-5kg of ragwort consumed over the lifetime of the horse. With the average lifespan of horses being 30+yrs, it is easy for these animals to reach the toxic dose over their lifetime.
Ragwort grows well on poor soil and is commonly seen on wasteland. The seeds are dispersed on the wind but once they have found ground they can stay in stasis for up to 20 years before growing and flowering. It is a reportable weed to local authorities and they have the power to order land owners to clear it from the ground.
Life cycle:
- Takes 2 years to fully grow and flower
- Dense rosette of leaves in first year
- Bright yellow flowers in year 2 on 30-100cm woody stems
- Each plant produces thousands of seeds which can lie dormant in the ground for up to 20 years before growing.
Clinical signs of ragwort poisoning:
Can be subtle until the end stages of chronic liver failure.
- Weight loss
- Poor coat
- Yawning
- Abdominal pain (colic).
- Diarrhoea, constipation and straining.
- In-coordination.
- Skin photosensitisation.
- Head pressing.
- Apparent blindness.
- Coma and Death
Jaundice is not a common sign of liver failure in horses.
Management:
- Good pasture management is imperative.
- Herbicides – Spray it when the plant is at the rosette stage and don’t wait for the stem to appear.
- Manual control when it should be uprooted, removed, and burned.
Mowing and cutting ragwort encourages it to grow back more quickly.
The consequences of ragwort ingestion are very serious and causes upwards of 300 unnecessary equine deaths per year. If you want to discuss this further we are more than happy to talk to you.