Plants Causing Liver Disease & Sunlight Sensitivity in Pastures

Identification: Narrow, linear, fleshy leaves; round stem; single bulb. White flowers in umbel borne on leafless flower stalk. Strong onion odor.

Habitat: Meadows, pastures

Animals Affected: Cattle are most susceptible, horses and dogs semi-susceptible; sheep and goats most resistant.

Toxin family: Alkaloids: damages red blood cell metabolism.

Other: Most poisonings are due to animals fed with cull domestic onions—rarely from wild onions. First sign of toxicity is generally dark red-brown urine, weak pulse, onion breath. Causes milk to taste like onion –onion flavor will disappear if animal is cut off from eating onions for 24 hours.

Identification: Up to two foot winter annual/biennial. Pubescent, alternate leaves two to three times pinnately compound, with linear segments. Flowers a raceme of tiny yellow flowers and fruit a long narrow pod, maturing from the bottom of the plant, up.

Habitat: Waste areas, roadsides and disturbed sites.

Animals Affected: Cattle

Toxin Family: Unknown

Other: Causes sporadic poisoning presenting as blindness and the loss of use of tongue and throat; or as liver disease and photosensitization.

Identification: Perennial with dimorphic stems. Vegetative stem has whorls of fine green jointed branches. Reproductive stem is flesh colored, unbranched, with a single cone at its tip

Habitat: Moist to wet forests, meadows, swamps, roadsides, areas with high water tables

Animals Affected: Primarily horses

Toxin family: Thiaminase; causes Vitamin B deficiency

Other: Symptoms include weight loss, diarrhea and weakness, leading to immobility and death. No loss of appetite. All plant parts are poisonous. Becomes increasingly toxic when dry, in hay.

Identification: One- to three-foot perennial. Erect stems, rust colored at base. Opposite, oblong leaves covered with transparent dots. Bright yellow flowers in cymes, often with black dots on petal edges.

Habitat: Pastures, rangeland, open timber, prefers well- drained soil.

Animals Affected: Cattle, sheep and horses.

Toxin Family: Hypericin (a photoreactive pigment) from the glandular dots on leaves is absorbed after ingestion, causing photosensitivity (skin cell death). Generally primarily affects white-skinned animals, rarely death occurs.

Other: Causes blisters around the mouth, eyes, ears, nose and feet when exposed to light Young plants palatable, mature plants not as much. Toxic at all growth stages. Remains toxic in hay.

Identification: Perennial solitary ferns up to three meters tall. Creeping rhizomes, leather fronds and densely hairy on the underside. Brown spores on the underside of frond segments. New growth emerges as fiddlenecks

Habitat: Open woods, roadsides, burned areas, prefers neutral to acidic soil

Animals Affected: Primarily horses, also cows and sheep

Toxin Family: Thiaminase, ptaquiloside

Other: Thiaminase causes thiamin deficiency in horses and pigs. Animals must eat large quantities and the deficiency is characterized by central nervous system depression. Ptaquiloside is a carcinogenic and bone marrow depressant norsesquiterpene glycoside affecting cows and sometimes sheep. Newly emerging fiddleheads are especially toxic and palatable, but animals must eat their weight over several months for disease to develop. Consumption over long periods will cause carcinogenic tumors in the bladder and other parts of the digestive tract. Bracken fern can also cause retinal degeneration and blindness in sheep. Toxins remain in hay and silage. Not highly palatable. All parts poisonous, root stock especially.

Identification: Erect, rhizomatous perennial. Alternate leaves are broadly elliptic and trifoliate (unlike lupine with five or more leaflets). Flowers are yellow and pea- like and grow in dense terminal racemes up to 4" long. Seed pods are densely haired and curved.

Habitat: Roadsides, pastures and rangeland

Animals Affected: Cattle

Toxin Family: Quinolizidine alkaloids causing muscle degeneration.

Other: Animals that have eaten false lupine show a reluctance to move and muscle tremors if forced to move. Not palatable.

Identification: Prostrate, pubescent annual. Pinnately compound opposite leaves with oblong leaflets. Solitary yellow flowers in leaf axils. Fruit is a small, spiny capsule

Habitat: Waste areas and roadsides

Animals Affected: All livestock

Toxin Family: Steroidal sapogenins and physical injury

Other: Causes insoluble crystalloid substance in bile ducts, blocking the biliary system and causing photosensitivity. Can also cause neurological symptoms and incomplete paralysis. Burrs are injurious to livestock and humans.

Identification: One to three foot annual with many branching stems. Leaves are opposite, lance shaped and clasp the stem. Flowers occur singly at stem ends and are bright pink.

Habitat: Cultivated fields, roadsides, waste areas

Animals Affected: Most livestock

Toxin Family: Saponin

Other: Can cause liver degeneration and death if eaten in large quantities. Seeds are especially poisonous to livestock

Identification: Four- to five-foot bushy annual. Large triangular, rough, glandular leaves. Flowers produced in leaf- axils. Blooms in summer, female flowers become bur with hooked bristles.

Habitat: Cultivated fields, pastures, barnyards, esp. sandy soils. Seeds germinate quickly with receding water

Animals Affected: All livestock

Toxin Family: Sulfated glycoside (Carboxyactractyloside) causing liver necrosis.

Other: Death occurs rapidly. Seedlings and seeds are very toxic, but toxins are not present in mature plants. Seeds are rarely eaten as they are contained in a bur. Toxicity remains in hay and silage. Burs also cause economic damage to wool producers.