Cockleburs (Xanthium spp.) are herbaceous annual plants with worldwide distribution, and their consumption by livestock can lead to toxicity and illness. Cocklebur toxicosis is associated with the ingestion of the seedlings or the dicotyledonary stage of the plant. The toxic principle, carboxyatractyloside, is present in the seeds and young seedlings, especially during the cotyledonary stage of growth. Cockleburs are commonly found in North America and can be fatal when consumed by livestock, including cattle, sheep, swine, and poultry.

Clinical signs of cocklebur intoxication in cattle include:

• Depression
• Weakness
• Anorexia
• Reluctance to move
• Opisthotonus (abnormal posture with the back extremely arched due to muscle spasms)
• Nausea and vomiting
• Weakness, prostration, and labored breathing
• Abnormal posture with the back extremely arched due to muscle spasms
• Leg paddling and convulsions when lying down
• Coma and death

Cockleburs can also cause damage to livestocks mouths and other sensitive tissues when they ingest the spiny capsule. The minimum lethal dose of cocklebur seeds is about 0.3% of the animals body weight. Diagnosis of cocklebur toxicosis can be difficult, as the clinical course of the disease is often only a few hours, and signs may not be observed.