Common Name
Botanic Name
Xanthium L.
Plant Family
Cockleburs prefer waste areas and disturbed soils, often around livestock facilities. Cockleburs are especially common around edges of ponds and resevoirs where soil is exposed by the receding water.
Throughout North America
Animals Affected
Pigs, and less often cattle sheep
Toxic Principle
Carboxyactractyloside, a sulfated glycoside, is present in high concentration in the burs and the 2-leafed cotyledon stage. Toxicity disappears by the 4-leaf stage, and is not present in the mature plant. The liver appears to be the primary target organ. Fatalities occur when 0.75% to 3.0% body weight of cotyledons are consumed. The toxin is a potent inhibitor of oxidative phosphorylation by inhibiting the Adenine Nucleotide Translocase (ANT).
Cockleburs are annual, bushy weeds 2-5 feet tall, with stout stems, often with red spots. The leaves are large, rough, glandular, triangular from 2-14 inches long and 1-8 inches wide. Flowers are produced in the leaf axils, the inconspicuous male flowers being clustered at the top, with the larger female flowers towards the base. The characteristic oval burs are covered by hooked spines. Each bur contains 2 seeds which can remain fertile for years.
Vomiting and abdominal pain. The spiny burs are also a mechanical source of injury to animals causing oral injury when consumed.
Supportive therapy may attempted. Mineral oil via stomach tube may help in decreasing further absorption of the toxin.
Nervous System
Severe depression, ataxia, recumbency and convulsions. Apparent blindness and brain lesions have been observed.
Renal System
Granular and hyaline casts are common in the urine due to renal tubular nephrosis
Integumentary System
The burs also cause economic losses to the wool producer because they become tangled in the fleece.
Hepatic System
Acute hepatocellular necrosis as indicated by marked elevation of serum liver enzymes. Severe hypoglycemia is a common finding in acute cocklebur poisoning.
Elevated liver enzymes, severe hypoglycemia, granular casts in the urine. Acute, diffuse centrilobular and paracentral to panlobular coagulative necrosis in the liver is typical.
Special Notes
Cockleburs are prolific seed producers, and the seeds may remain viable for years before germinating. The plants should be destroyed before they form the burs. --1. Stuart BP, Cole RJ, Gosser HS. Cocklebur (Xanthium strumarium, L. var. strumarium) intoxication in swine: review and redefinition of the toxic principle. Vet Pathol. 1981 May;18(3):368-83. doi: 10.1177/030098588101800310. PMID: 7257080. --2. Witte ST, Osweiler GD, Stahr HM, Mobley G. Cocklebur toxicosis in cattle associated with the consumption of mature Xanthium strumarium. J Vet Diagn Invest. 1990 Oct;2(4):263-7. doi: 10.1177/104063879000200402. PMID: 2095279. --3. Botha CJ, Lessing D, Rasemann M, van Wilpe E, Williams JH. Analytical confirmation of Xanthium strumarium poisoning in cattle. J Vet Diagn Invest. 2014 Sep;26(5):640-5. doi: 10.1177/1040638714542867. Epub 2014 Jul 10. PMID: 25012081.
Two leafed stage of cocklebur when it is most tox
Cockleburs (Xanthium spp.)