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Submitted to: Veterinary Clinical Toxicology
Publication Type: Book / Chapter Publication Acceptance Date: 1/1/2003 Publication Date: 1/1/2004 Citation: Stegelmeier, B.L. 2004. Pyrrolizidine alkaloid containing plants (senecio, crotalaria, cynoglossum,amsinckia, heliotropium and echium spp.). Veterinary Clinical Toxicology. Interpretive Summary: Pyrrolizidine alkaloids (PA) are found in many different plants throughout the world. About half of the identified PAs are toxic and several can cause cancer. In many locations, PA-containing plants are troublesome weeds that are not easily controlled. PA-containing plants can grow in open ranges and fields where they may replace nutritious plants. Most PA- containing plants are not palatable and livestock avoid eating them if other forages are available. However, as they invade fields or crops, plant parts or seeds can contaminate prepared feeds and grains, which are then readily eaten by many animals. Human poisonings most often are a result of food contamination or when PA containing plants are used for medicinal purposes. Finding toxic plants where animals may eat them, discovering sick animals that have liver changes consistent with PA- intoxication are used to identify poisoned animals. PA metabolites can also be detected in serum or liver samples of poisoned animals. The need for additional research including development of technology to monitor food and feed quality, better diagnose poisoned animals, and the effects of chronic low dose PA exposures is discussed. Technical Abstract: Pyrrolizidine alkaloids (PA) are found in many different plants throughout the world. About half of the identified PAs are toxic and several are carcinogenic. In many locations, PA-containing plants are introduced species that are considered invasive, noxious weeds. Both native and introduced PA-containing plants often infest open ranges and fields, replacing nutritious plants. Many are not palatable and livestock avoid eating them if other forages are available. However, as they invade fields or crops, plant parts or seeds can contaminate prepared feeds and grains, which are then readily eaten by many animals. Human poisonings most often are a result of food contamination or when PA containing plants are used for medicinal purposes. Current diagnostic techniques include exposure to toxic plant, post mortem and histologic changes consistent with PA- intoxication, and chemical detection of PA metabolites in serum or liver samples. The need for additional research including development of technology to monitor food and feed quality, better diagnose poisoned animals, and the effects of chronic low dose PA exposures is discussed. |
