- Distinguishing features
- Lupines are perennial or sometimes annual herbs with palmately compound leaves; their leaflets are narrow; their flowers are in terminal racemes, pea-like, often blue, but yellow or white in some species. They have pods up to 1 inch in length.
- Lupines are in the Legume family which is characterized by irregular, five-petaled flowers with a central "keel." Flowers are most often blue; occasionally white, red or yellow varieties are seen. Leaves: the leaf, a palmately compound leaf with five to seven elongated, ovoid leaflets, is somewhat distinctive.
- Geographic range
- Both cultivated garden lupines and native lupines of the western rangelands are toxic. In rangelands, they occur from the dry, open ranges of the Great Plains to the Rocky Mountains.
- Toxic principle
- Lupinine, a quinolizidine alkaloid, induces nicotinic effects in animals. Leaves, seeds and fruits all contain lupinine, which is retained in dried plants. Pods may concentrate the toxin, becoming a source of poisoning during the winter season when livestock are moved through infested areas or contaminated hay is fed.
- Lupines are a major toxic problem in range sheep. Lupines are toxic when ingested at 1% or less of body weight.
- Clinical signs
- Salivation, ataxia, seizures and dyspnea are major acute clinical signs and are more common in sheep that in cattle.
- Head-pressing and excitement may also be seen.
- Effects not related to the nervous system include the "crooked calf syndrome" (i.e., carpal flexure, torticollis and scoliosis in calves exposed in utero during days 40-70 of gestation). The toxic principle for this effect is the alkaloid anagyrine. Interestingly, anagyrine is not teratogenic to sheep fetuses.
- Laboratory diganosis
- not useful
- characteristic limb and spinal deformities
- Oral detoxification and control of seizures in severely affected animals is the only recourse.
- through correct range management is preferred. Alter grazing rotations so that cows are not exposed to lupines between days 40 to 70 of gestation.
It has been proposed that cattle are affected by anagyrine due to ruminal metabolism of the alkaloid to a teratogenic metabolite. The mode of teratogenic action may involve an immobilizing affect on the fetus; skeletal malformations occur because the fetus remains in one position for extended periods of time.
Read more in the Poisonous Plants of Pennsylvania Publication