Senecio jacobea (ragweed, St James-wort, staggerwort, cankerwort, stammerwort, stinking nanny). Related species: S. vulgaris (groundsel); S. lautus (common fireweed). A member of the plant family COMPOSITAE. Very common perennial plant, with a 90cm stem, lobed broadly toothed leaves and bright yellow flowers arranged in large, flat-topped bunches (corymbs). The fruit (akenes) are hairy with a single tuft.


[affected.gif] Animals most affected
Cattle, horses, (all other animal species).


[etiology.gif] Etiology
Note: poisoning involving S. jacobea has never been well documented in France despite the prevalence of the plant. However in the UK there are many reported incidents involving exposure to ragwort. The plant should thus be borne in mind when cattle present with a hepatic syndrome of unknown etiology.
Poisoning occurs when the fresh plant material is ingested or, more frequently, when it contaminates hay or silage.


[toxic.gif] Toxicity
Contains pyrrolizidine alkaloids including:
jacobine, jacodine, jaconine and retrorsine, which are all hepatotoxic. Toxicity is maximal during the first stage of plant growth. Drying does not reduce the toxicity of the plant.

Oral doses:
LD quantity of fresh plant expressed as a percentage of body weight:
horses, cattle 4-8
sheep, goats 200-300


[clinical.gif] Clinical features
Present after a latent period of several weeks to several months. The clinical signs are extremely diverse and without any special characteristics:


Generally fatal outcome. Although acute poisoning is quite uncommon, it may result where there has been a massive ingestion over a short time, with tachypnoea, weakness, jaundice and death within several hours. In horses, photosensitization may develop following ingestion of the plant.



[lesions.gif] Lesions


[treatm~1.gif] Treatment
No antidote. Symptomatic care may be attempted but is of little value.