Centaurea solstitialis is toxic to horses. The reported severity is severe. Also known as Yellow Star-Thistle.
This plant is known to be potentially deadly!
If your animal ate this plant, call your veterinarian, the ASPCA Animal Poison Control on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661. Fees may apply.
Difficulty Swallowing Death Oral Irritation Yawning CNS Depression Difficulty Breathing Weight Loss
The color of each symptom follows the severity scale above.
Centaurea solstitialis, the yellow star-thistle, is a species of thorny plant in the genus Centaurea, which is part of the family Asteraceae. A winter annual, it is native to the Mediterranean Basin region and invasive in many other places. It is also known as golden starthistle, yellow cockspur and St. Barnaby's thistle.
Grazing of the plant by horses can cause nigropallidal encephalomalacia or "chewing disease", a neurological condition. The disease generally follows consumption of 60–200% of the horse's body weight over an extended period of a month or more, or 2.3–2.6 kilograms (5.1–5.7 pounds) of star-thistle per 100 kg (220 lb) body weight per day. Though star-thistle is most dangerous when it is the only plant available or is delivered as a contaminant in dried hay, horses may develop a taste for it and seek it out. Many other grazing species, including mules and burros, are not affected.
Also recorded as Barnaby star-thistle, Barnaby's Thistle, Barneby star thistle, St Barnaby's Thistle, Yellow Centaurea and geeldissel.
More from the Asteraceae family:
Countries with the most wild observations, from GBIF data.