Poisonous Plants A / B

ACORNS (from Quercus spp.)

See Oak.

ALDER BUCKTHORN (Frangula alnus)

A decidious non-shiny shrub which will grow to about 3 metres high. It's native to Britain, though it originates from Scotland. It likes calcareous soils (soils containing calcium carbonate), prefering damp forests, bogs, scrubs and fenland. A preperation made from the bark of alder buckthorn is used as a mild laxative medicinally.

Poisonous principles and symptoms
The plant contains glycosides which produce purgative anthraquinones. The symptoms of poisoning with this shrub include diarrhoea, cramps, and a slight fever. Reported cases of poisoning in horses is are rare.

AUTUMN CROCUS(Colchium autumnale)

This plant is an outdoor ornamental grown for its autumn flowers. This plant is found only in garden cultivation or maybe as a houseplant.

Poisonous principles and symptoms
All parts of this plant are poisonous. It contains Colchicine and colchiceine. These chemicals withstand drying, storage, and boiling without losing their toxic qualities. Colchicine affects the central nervous system, paralyzing nerve endings and blocking neuromuscular connections. The symptoms of poisoning is the horse will collapse.

AVOCADO(Persea americana)

Dark green, pear-shaped fleshy fruits that grow on trees and are native to Central America. In the Philippines a piece of the avocado seed is applied to decayed teeth to relieve the pain.

Poisonous principles and symptoms
The avocado fruit's flesh is safe to eat. However, the seeds and skin of the fruit and the leaves and bark of the tree are poisonous to cattle, horses, goats, rabbits and other animals. Animals who eat the poisonous parts of the avocado can experience loss of appetite and sometimes liver and lung damage.

BANEBERRY (Actaea pachypoda)

The plants are predominately herbaceous, with colorless, acrid juice; sepals: 2 to many; petals: numerous or in some species absent, with the calyx colored like the corolla; stamens: rarely few, typically very numerous; pistils: few to many and spirally arranged (1 in Actaea); fruits: dry capsules, seedlike achenes, orberries; sepals, petals, stamens, and pistils all distinct and unconnected; leaves: often dissected petioles dilated at the base, sometimes with stipulelike appendages. It has white fruit (rarely red), the stigma wider than the ovary, and very stout fruiting pedicels. Found throughout the Commonwealth countries.

Poisonous principles and symptoms
All parts, especially roots and berries, are toxic. The toxic compound is unknown but probably is an essential oil or poisonous glycoside. As few as six berries have been reported to cause severe symptoms. Symptoms of poisoning include acute stomach cramps, increased pulse, dizziness and circulatory failure. Symptoms usually disappear after 3 hours.

BLACK BRYONY (Tamus communis)

This climbing plant is most likely found at the edges of forests, scrubs and hedges. It is most commonly found in Souther England, the Midlands and Wales.

Poisonous principles and symptoms
Very little is known about the poisonous principles of this plant, but it is believed to be a glycoside. Symptoms may include a decreased appitite with severe abdominal pains, a hight temperature and profound sweating. There have been some reported causes of fatal horse poisoning.

BLACK CHERRY(Prunus serotina)

A native tree found that is occasionally cultivated as an ornamental. This tree contains chemicals that can release hydrogen cyanide in animals.

Poisonous principles and symptoms
The toxic parts of this tree are the leaves, seeds and twigs. Two cyanogenic glycosides are found in the black cherry. Amygdalin and prunasin are found in the leaves, twigs, and seeds. Hydrogen cyanide is formed when the glycosides are hydrolyzed by plant enzymes after damage or by rumen organisms. The symptoms of poisoning from this tree are labored breathing, staggering, muscle spasms, labored respiration, body paralysis, coma and finally death by asphyxiation (Death caused by inadequate oxygen, the presence of noxious agents, or an obstruction of normal breathing). Death is often swift. Postmortem findings include bright red blood and congestion of internal organ.

BLACK LOCUST (Robinia pseudoacacia)

Black locust is a naturalized tree or shrub that is planted as an ornamental in the warmer parts of Canada.

Poisonous principles and symptoms
The toxic parts of this tree/shrub are the leaves, bark and seeds. Robin (or robinin) and phasin, which are toxic proteins called toxalbumins, are present in this shrub/tree. A glycoprotein that joins red blood cells togehter has been extracted from the plant. It is not clear if this is robin or another substance. The symptoms of poisong are anorexia,, nausea, paralysis of the hind end, pupil dilation and weakness. Symptoms of colic can also occur and death in severe cases. Postmortem findings usually show mucous inflammation of the gastrointestinal tract and occasional severe gastroenterititis. In some cases a yellowish pigmentation of the membranes occurred.

BLACK NIGHTSHADE (Solanum nigrum)

An erect branched annual (occasionally biennial) plant. It measures from under 10 centimetres up to 60 centimetres in height and is an extremely successful and troublesome weed in farmed land.

Poisonous principles and symptoms
This weed, expecially its berries contain toxic alkaloids, nitrates and nitrites. The symptoms of poisoning may include severe abdominal pain, staggering and depression. The weed varies in toxicity according to several factors like climate, season and type pf soil. This may accound for conflicting reports concerning its toxicity. There have been a few reports with horses.

BLACK OAK (Quercus velutina)

Black oak is a native tree that is found only in southern Ontario. The acorns from this tree contain a significant quantity of toxic phenolics.

Poisonous principles and symptoms
The acorns and the leaves are highly poisonous containing gallic acid, pyrogallol and tannic acid. Symptoms of poisoning are unknown.

BLACK WALNUT (Juglans nigra)

Black walnut has been planted as a cultivated tree. The shavings of wood from this tree have caused laminitis in horses in the United States, when used in stables.

Poisonous principles and symptoms
The toxic parts of this tree are the bark, mature fruit and the wood. It contains the toxic chemical juglone. Symptoms of poisoning are an inability to coordinate voluntary muscular movements, rapid breathing, dapression, laminitis, little enerygy and RECUMBENCY(Leaning, resting, or reclining positions).

BOUNCING BET(Buxus sempervirens)

A very common and familiar weed of summer and autumn throughout the United States, bouncing bet is found in colonies along roadsides and railroad tracks, in meadows, and waste areas. It is a knee-high, spreading, perennial weed with jointed stems. The leaves are opposite, simple, toothless, and slightly hairy. Phlox-like, flat-topped flower clusters consist of white or pinkish-white to red blossoms that have five petals, each with a slight notch at the tip.

Poisonous principles and symptoms
All partsof this plant especially the seeds and roots contains saponins, substances that when mixed with water produce a soap-like foam. These saponins produce gastrointestinal irritation upon ingestion. Animals will typically avoid eating this plant, however they may ingest it if extremely hungry and no better feed is available, or if parts of the plant (especially the seeds or the roots) are incorporated into prepared feeds. The plant needs to be consumed for several days before toxic signs are noted, which can include: mild depression, vomiting (in those species that can vomit), abdominal pain, diarrhea (which may become bloody). Overall, this toxicosis is not encountered frequently.

BOX (Buxus sempervirens)

A native evergreen shrub / tree that is limited to southern England and is found on chalk or limestone and in forests and scrubland. Box is cultivated as a garden hedging plant.

Poisonous principles and symptoms
All the parts of this plant is poisonous, but due to its horrible taste most animals will avoid it. It contains a substance called buxine which is composed of a complex group of steroidal alkaloids. Symptoms of poisoning include diarrhoea, incoordination, convulsions and coma. Respiratory failure is the usual cause of death in the animal. Poisoning has been recorded in horses.

BRACKEN (Pteridium aquilinum)

A fern plant that measures up to 2 metres in height and is common around forest areas. It prefers acid soil and has a creeping underground root system, from which the leaves sprout in the spring, dying down again in the autumn.

Poisonous principles and symptoms
Bracken is carcinogenic as well as containing an enzyme, thyaminase, which can lead to thiamin (vitamin b1) deficiency. Symptoms of thiamine deficiency are incooordination, pronoucned heart beat after a mild workout and muscle tremors. If it is left untreated (by means of intravenuous administration of thiamine) then convulsions and death will be the outcome. The symptoms gove rise to the old name of 'bracken staggers'. Bracken is a common cause of serious or fatal poisoning in horses.

BROOM (Cytisus scoparius)

This shrub is found mainly in dry hilly areas throughtout Britain, western Europe and Scandinavia. Used in herbal medicine, it has both cardio-active and diuretic properties, and it should only be used medically by appropriately qualified and experienced practitioners. The tops of Broom are a traditional anthelmintic.

Poisonous principles and symptoms
This plant contains alkaloids, which can depress the heart and nervous system and also paralyse the motor nerve endings. There have yet to be any reported cases of poisoning in horses, most probably due to the fact that the small leaves and wiry stems make the plant unattractive to them.

BUCKEYE HORSECHESTNUT (Aesculus glabra Aesculus hippocastanum )

The thick twigs of these medium-sized trees have glistening buds in spring and bear opposite leaves composed of five leaflets in a finger-like arrangement. The yellowish flowers rise in large, upright, dense, candle-like clusters at branch ends during June. The prickly fruit contains 1 to 3 nutlike seeds, glossy and leathery brown with a pale scar on each that gives the tree its name. These trees commonly grow in rich, moist woods or along river banks and are often planted as ornamentals.

Poisonous principles and symptoms
Buds, nuts, leaves, bark, seedlings, and honey contain saponic glycoside aesculin in addition to suspected alkaloids. The toxins in Buckeye and Horsechestnut affect the gastrointestinal tract as well as the nervous system. . Symptoms of poisoning include salivation, abdominal pain, and diarrhea. If enough was ingested, neurologic signs may develop, including trembling, staggering, and difficulty in breathing. Toxicity may then progress to collapse, paralysis, coma and death.

BUCKTHORN (Rhamnus cathartica)

A thorny deciduous shrub which reaches a height of about 4 - 6 metres. It prefers calcareous soils. Buckthorn can be used medicinally as a laxative. Other common names for this shrub are - Purging buckthorn and Common buckthorn.

Poisonous principles and symptoms
See Alder Buckthorn.

BUCKWHEAT (Fagopyrum esculentum)

Buckwheat is native to Central Aisa and is cultivated on a small scale in Britain and also other parts of the world. In America it is the sorce of buckwheat flour which is used to make pancakes. It is used in herbal medicine for conditions involving the circulatory system. It is found wild sometimes on waste ground.

Poisonous principles and symptoms
A pigment called fagopyrin is believed to be the poisonous principle of this weed, but not much is really known about the chemical profile in this respect. The dehusked seeds are believed to be harmless and used quite commonly in animal feeds; but, aninals that have ingested a large quantity of the fresh or dried plant have developed a photosensitivity to the sunlight. The symptoms from this poisoning include reddening of the skin which may develop lesions, nervousness, agitation and emaciation.

BULB-BEARING PLANTS(Ranunculus acris)

Hippeastrum vittata (amaryllis, amaryllid family). A houseplant that blooms in only a few weeks after forcing in the wintertime. At first one or two 1 to 3 feet tall, naked stalks appear, each bearing from one to four large, six-petaled, red, blue, white, or bicolored flowers. Later several sword-shaped, fleshy leaves develop from the base of the plant.
Hyacinthus spp. (hyacinth, lily family). These potted or garden plants grow from a 1 to 2 inch diameter bulb. The 8 to 12 inch long leaves are narrow, somewhat trough-shaped, and fleshy. The small fragrant, white, pink, or blue lily-like flowers are borne on a leafless stalk that is taller than the leaves.
Iris spp. (iris or blue flag, iris family). These commonly grown garden perennials also occur wild in wet meadows, marshes, roadsides, lakeshores, and stream banks. Branching, fleshy rootstocks bear clusters of long, sword-like leaves in which the base of each leaf is folded over the base of the next higher leaf. The flowers, blue with a yellow heart in our wild species but purple, blue, yellow, or reddish-brown in cultivated varieties, have three upright "standard" petals and three pendant "fall" petals. The fruit is a dry capsule.
Convallaria majalis (lily-of-the-valley, lily family). A familiar low-growing garden perennial, forms dense clumps from slender rootstocks called "pips.'' The lily-like leaves are parallel-veined, and from them rise flower stalks that bear small white blossoms all on one side. The flowers are bell-like and fragrant and rarely develop into the red to orange-red berries.
Narcissus spp. (daffodil, jonquil, narcissus; amaryllid family). Springtime in Indiana is officially proclaimed by the yellow trumpets of daffodils. These perennials produce lily-like leaves and slender stalks that each bear a conspicuous orange, white, or yellow flower with six petals, parts of which fuse to form the trumpet.

Poisonous principles and symptoms
This group of plants is divided into two sections. The first section includes lily of the valley, and the second section includes the other bulbs.
1. Lily of the valley is the far more dangerous plant, producing a mixture of many cardiac glycosides, especially convallatoxin. Toxic signs in pets after they chew on the plant would include stomach upset, irregular heartbeat, convulsions, and death if sufficient quantities are consumed. The toxin in lily of the valley acts in a similar manner to the toxin in foxglove, a plant from which digitalis, a powerful cardiac medication, is derived.
The bulbs or corms of tulip, daffodil, jonquil, narcissus, amaryllis, and iris produce primarily gastrointestinal signs (diarrhea) after consumption, and are not as toxic as lily of the valley. Pets are more likely to come into contact with these plants than are horses or livestock, however, livestock have been poisoned when grazing wild-growing iris and eating the rootstocks.

BURNINGBUSH(Ranunculus acris)

Burningbush is an ornamental shrub. The poisonous parts of this plant are the bark, leaves and seeds. Several cardiac glycosides have been found in the seeds of this plant, including evomonoside, whose aglycone is digitoxigenin. Alkaloids make up about 0.1% of the seeds, including evonine. The toxicity of the alkaloidal fraction has not been studied. Cardiac glycosides are also found in the leaves and bark (but the alkaloid content is too low to be of any consequence. Symptoms of poisoning include constipation, an elevated heart rate and finally death.

BUTTERCUP (Ranunculus acris)

A hairy perennial plant found in pastures and meadows. It prefers alkaline soil. Other common names for this plant are Meadow buttercup, Filed buttercup and Tall buttercup.

Poisonous principles and symptoms
Meadow buttercup, the same as other plants of the same family, such as the greater spearwort (Ramunculus lingua), contains a toxic compound known as protoanemonin. In large quantities, this compound will cause salivation, as well as inflammation of the mouth and abdominal pains with convulsions usually proceeding death. However, there have been very few cases of posioning involving the Ranunculus family reported. Even though the plants must be regarded as a potentual risk. Protoanemonin is an unstable compound which is changed to a non-toxic substance when the plant is dried. This means that hay containing any of the Ranunculus family is safe to feed horses.