Veterinary Medicine Library

Lupine (Lupinus)

| Description | Distribution | Conditions of poisoning | Control | Toxic principle | Clinical signs | References



Lupine is a herbaceous perennial, 12-26 inches tall. Leaves are alternate, palmately divided into 10-15 narrowly oblong leaflets. The leaflets are smooth or hairy above, and very hairy beneath. Bonnet-shaped flowers are born in racemes on a single center stalk 4-10 inches long. The flowers bloom in early to mid summer displaying their wide range of colors from deep blue, purple, light blue, lavender, rose, pink, yellow, and white. The fruit is a pod about one inch long containing several somewhat flattened seeds. The seeds are cream-colored and irregularly circular, and no more than 1/4 inch in diameter.

Lupine in early growth Lupine with seed pods

  Lupine-early growth

Lupine with seed pods


Lupines thrive in dry open fields and prairie/wood area. Horticultural variety of lupine has been a favorite of many gardeners for ages. Though Lupine in Illinois is most frequently seen in flower gardens, most of the approximately 100 native species are found throughout the U.S. and Canada, mainly in states west of the Rockies. A blue wild variety of lupine covers Texas open ranges in early summer, earning the rank of the State Flower. A different wild variety is also widely encountered in early summer by the visitors of the Olympic National Park in the State of Washington.

Conditions of poisoning

Poisoning varies depending on lupine species and varieties, and it is difficult to pin point to specific plant or animal since different animals become susceptible in different ways under varying range conditions.

Species and taxonomic differentiations between species are insufficiently characterized. Different lupines produce varying syndromes in a a given species of livestock. Seasonal variation in toxicity in a given species of lupine exist and many species are acceptable forage under range conditions. Plants which are in the preflowering stage of maturity are unlikely to be hazardous, under normal range circumstances, except in the case of L. leucophyllus which may cause toxicosis as a result of consumption of young plants. Alkaloids are not lost upon drying. Range hay may be highly toxic is the seeds are retained; this occurs when the majority of the pods are immature; mature pods open when drying and the seeds are dropped as the hey is hndles. For many lupines, the time and degree of seeding varies year to year.

Most losses occur under conditions in which animals consume large amounts of pods in a brief period, such an area, trailing animals through an area where the grass is covered by snow but the lupine is not or when feeding podded lupine hay, which apparently palatable. Most serious poisoning, therefore occur in the fall; lupine remains green after other forage has dried.

Toxic Principle

More than a dozen quinolizidine alkaloids, but some piperidine alkaloids and other types of alkaloids have also been isolated from species of Lupinus. These alkaloids are largely nicotinic in effect. The nitrogen oxides of some of these bases have also been detected in some lupines. The alkaloids are present in the foliage but the greatest concentration is in the seeds.

Clinical signs

Signs include characteristic labored breathing (snored) in sheep, with depression , salivation, ataxa, clonic spasms, head pressing tremors, seizures and coma, and frequently death. Death may be preceded only by coma and not other signs (no struggling) or alternatively, preceded by violent attacks on other aimals or objects. Signs may appear as early as one hour after ingestion or as late as 24 hours after consumption. Death may occur iwthin one day or occur several days later and is a result of respiratory paralysis. Cattle under range conditions rarely display clinical signs.

Other References:

Lupinus entry in Wikipedia

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