Common cocklebur (Xanthium strumarium
) is an annual erect, branching plant which is native throughout North America. Cocklebur has large, simple, alternate leaves with serrated edges; they are covered with minute hairs on both sides. The brown or greenish brown fruits or burs are covered with stiff, hooked spines and contain two seeds. It's flowers are found in leaf axils or terminally on branches.
Cocklebur is toxic to livestock, with the capability of causing acute liver failure. The primary hepatoxin is a carboxyatractyloside, which is a sulfated diterpene glycoside. The majority of the toxin is found in the seed and cotyledons. Birds need only ingest 0.75 to 3% of their body weight of X. strumarium
seeds to result in acute toxicity signs. Younger poultry are more at risk of toxicity and most cases of poisoning in animals occur in the spring and summer.
Poultry may develop acute or chronic toxicity as a result of consumption of X. strumarium
. In acute cases, death is usually due to liver failure and may occur within hours after onset of clinical signs. Birds that survive acute poisonings usually will develop signs of chronic liver disease.