Читать книгу Plants Poisonous to Live Stock - Harold Cecil Long - Страница 5
CHAPTER II
RANUNCULACEÆ.
ОглавлениеTraveller’s Joy (Clematis Vitalba L.). The extent to which this species is poisonous is not clear, though all parts are stated to be poisonous, acrid and narcotic, while the juice tends to blister the skin. It is remarked by Cornevin that it is less poisonous in spring, when the ass and goat browse on it to a considerable extent without serious trouble, than later, when it cannot be eaten without danger.
Toxic Principle. Traveller’s Joy appears to contain strongly poisonous substances which have not been closely investigated. Greshoff found a Saponin in the leaves[2]. The poison is dissipated by heat.
2. Kobert states that various species of Clematis, Ranunculus, Anemone, and also Caltha palustris and Trollius europæus, contain Anemonal or Pulsatilla-camphor, which causes strong local irritation, burning and swelling in the mouth, vomiting, intestinal inflammation, etc.
Symptoms. When eaten in quantity the young shoots are diuretic, violently purgative, causing dysentery, and in rare cases death. Applied to the exterior it is irritating and even vesicatory. (Cornevin.)
REFERENCES.
63, 81, 101, 130, 161, 233.
Anemone (Anemone sp.). Both our native species of Anemone appear to be more or less poisonous in character: the Wood Anemone or Wind Flower (A. nemorosa L.), and also the Pasque Flower (A. Pulsatilla L.). These plants, the former of which grows in woods and damp shady spots in fields, and the latter on chalk downs and limestone pastures, may on occasion be taken by stock in early spring, when green herbage is not too plentiful, but deaths appear to be rare, even if they have occurred. All parts of the plants contain a toxic principle, which is volatile and destroyed by drying.
Toxic Principle. The toxic substance is stated to be Anemone-camphor (oil of Anemone) which imparts a bitter taste to the plants, and itself gives rise in the plant to Anemonic acid and Anemonin (C10H8O4), a very poisonous, narcotic substance, stated to be neither a glucoside, nor an alkaloid, but a ring ketone with the properties of an acid anhydride.
Symptoms.—The symptoms recorded by Cornevin in the poisoning of animals by the fresh plants are nausea, coughing, vomiting (if possible), stupefaction, muscular tremors, and violent colic, accompanied at times by hæmaturia and always by diarrhœa and dysentery. There are pronounced respiratory and heart troubles.
Pott confirms the symptoms of hæmaturia, diarrhœa, and inflammation of the stomach and intestines in the case of A. Pulsatilla when fed in the green condition. According to Esser, the plant poison affects the spinal cord and the brain, the symptoms being similar to those produced by Aconitum Napellus.
REFERENCES.
16, 63, 81, 191, 197, 198, 213, 233, 240.
Buttercups (Ranunculus sp.). A number of species of Ranunculus are acrid, irritant or severely poisonous, as the case may be. There are variations in the poisonous character according to the season, and some parts of the plant are more toxic than others. At the time the young shoots develop in the spring but little of the poisonous principle is present, and some (e.g. R. Ficaria) are not then poisonous, but a larger quantity of the poisonous principle forms later, and some species are especially dangerous at the time of flowering, after which the toxicity decreases with the maturity and state of dryness of the plant. The flowers are the most poisonous, and then the leaves and stem. It does not seem to have been demonstrated that the seeds of any species are dangerous, though Henslow states that the fruits of some species, when green, appear to be most intensely acrid.
Some species of Ranunculus are especially harmful (R. sceleratus, R. Flammula, and R. bulbosus), while others are less so (R. lingua, R. Ficaria, R. acris). The toxic principle is volatile, and buttercups are easily rendered innocuous by drying or boiling—so much so that when dried in hay they may be regarded as a nourishing food for stock, and are readily eaten. Indeed, R. repens is scarcely, if at all, injurious even when green, though a case of fatal poisoning to sheep said to be due to this species was reported in the Veterinarian in 1844. Fresh R. aquatilis is held to be quite harmless, and has been used as a fodder. “Along the banks of the Hampshire Avon, and other places in the same neighbourhood, it is used by the peasantry as fodder. They collect it in boats and give it to their cows and horses, allowing the former about twenty to thirty pounds a day. One man is said to have kept five cows and a horse, with little other food but what they could pick up on the heath, using no hay but when the river was frozen. Hogs eat it and will live upon it alone until put up to fatten.” (Johnson and Sowerby—Useful Plants of Great Britain.)
R. sceleratus L., or Celery-leaved Buttercup, is probably the most toxic species, and it is stated that in man a single flower may cause poisonous symptoms resembling those due to Anemone and Colchicum. It is considered especially dangerous to cattle, and has caused many losses: among its French names are Mort aux Vaches, and Herbe sardonique. Poor people have been known to eat the young shoots when boiled, heat dispelling the poison.
R. Flammula L., the Lesser Spearwort, has repeatedly proved fatal to horses and cattle.
R. bulbosus L., the Bulbous Buttercup, is somewhat variable in toxicity, and is least dangerous after the flowers have dropped their corolla, and the bulb-like rootstock is most harmful in autumn and winter. The flowers are the most dangerous part.
R. Ficaria L., Lesser Celandine, varies in toxicity with locality and season, being most harmful at the flowering period. It is stated that wood-pigeons eat the roots with avidity, and that the young shoots have been eaten as a salad in Germany, as they are not toxic. An English veterinary surgeon (Flower) recorded that three heifers were poisoned by it (Vide Cornevin).
R. acris L., Acrid Buttercup or Tall Crowfoot, is a frequent cause of poisoning in cattle, and Cornevin says it is perhaps the species which causes the most accidents.
Toxic Principle. The buttercups contain an acrid and bitter juice, the chemical properties and composition of which are not well known, but it is believed that the substance is identical with the Anemonin of the Anemone sp. (q.v.). Beckurts isolated Anemonin and Anemonic acid from R. acer. Pott, however, states that the poisonous species contain the two alkaloids Aconitine and Delphinine.
Symptoms. The buttercups are acrid, burning and narcotic, causing irritation of the mucous membrane, with inflammation of the intestinal tract.
Cornevin shows that R. sceleratus induces gastro-enteritis, colic, diarrhœa with excretion of black foul-smelling fæces, vomiting when possible, falling-off in milk yield in cows, nervous symptoms, reduction in pulse, and stertorous respiration, dilation of the pupils, enfeebled condition, difficult mastication, spasmodic movements of the ears, lips, etc.,—followed in serious cases by convulsions, sinking of the eye in its socket, possibly stoppage, and death in 6 to 12 hours after convulsions first appeared.
In the horse symptoms substantially similar to the above have been recorded (Lander).
In cows, Pott records hæmaturia, and reddish or bitter milk.
Sheep after eating R. repens have been noticed to fall suddenly in the field; their eyes rolled, and some animals showed dizziness, and died with the head inclined over the left flank (Lander).
REFERENCES.
47, 63, 81, 112, 130, 140, 145, 170, 203, 204, 205, 213, 233, 235.
Marsh Marigold or King-Cup (Caltha palustris L.). Like the species of Ranunculus, the Marsh Marigold is to some extent poisonous in character, and both animals and man have suffered. Cattle have died from eating it, and Müller records the poisoning of many horses, one of which died. In general, animals refuse it, but may possibly eat it when pressed with hunger in times of scarcity of green herbage. Cornevin states that it has little or no acrid properties when very young, but that it is toxic by the time of flowering—acridity increasing with age.
Toxic Principle. The toxic character of the Marsh Marigold has not been fully investigated, though the presence of an alkaloid has been determined, and A. B. Smith states that the toxic properties are due to the alkaloid Jervine (C26H37O3N2H2O) and the glucoside Helleborin (C36H42O6). On drying—e.g. in hay—the plant becomes harmless, as in the case of most species of Ranunculus.
Symptoms. Cornevin records that cattle have died from inflammation of the digestive tract, and gives the symptoms as those of Ranunculus poisoning. There seem to be digestive troubles, diarrhœa, and loss of milk production, even (according to Rusby) when fed with hay. In the horse, there is colic, bloating, and inflammation of the bladder, while the urine is dark red. According to Cornevin, the symptoms are similar to those produced by Ranunculus sp. Pammel quotes Friedberger and Fröhner as stating that the plant causes hæmaturia. Five persons who ate it as a herb were “seized with violent sickness and pain in the abdomen, followed by diarrhœa and general œdematous swelling over the whole body,” but they recovered (Johnson and Sowerby).
REFERENCES.
63, 81, 140, 190, 203, 213, 233.
Hellebores (Helleborus sp.). Two poisonous species of hellebore may on occasion be taken by live stock, though rarely—Stinking Hellebore (H. fœtidus L.) and Green Hellebore (H. viridis L.). The much esteemed Christmas Rose (H. niger) is also toxic, but unlikely to be eaten by stock. In no case should trimmings of these plants from shrubberies, etc., be thrown to stock—cows have died from eating such trimmings. The two species first mentioned are equally toxic, all parts are poisonous, and drying does not render them innocuous. Cornevin records that animals have been killed by H. fœtidus, and says that 9½ oz. of the fresh root or 2½ oz. of the dried root are poisonous doses to the horse, while 120 to 150 grains are fatal to sheep. It was recorded in 1847 (Veterinarian) by Mayer that a horse was fatally poisoned through eating five half-pints of the chopped-up leaves of this species in two days in a bran mash. In regard to this species also Johnson and Sowerby write: “The Bear’s-Foot has been used as a vermifuge ever since the days of Hippocrates, notwithstanding its dangerous qualities. Every part of the plant is a violent cathartic, but far too uncertain in the degree of its action to be safely administered.”
Toxic Principle. Both species contain the poisonous glucosides Helleborin (C36H42O6), a highly narcotic and powerful poison; Helleborein (C26H44O15); and the alkaloid Jervine (C26H37O3N2H2O).
Symptoms. The Hellebores are cathartic, narcotic, and drastically purgative. Stupor is followed by death with spasms in the case of H. viridis (Pammel). In general there is in the horse and ox bloody purgation, salivation, attempts to vomit, and excessive urination, according to Lander, who cites Mayer as noting violent straining and the discharge of frothy mucus, but no effort to vomit, the heart action resembling that observed in Digitalis poisoning, showing periodic intervals of arrest in systole.
Müller gives the symptoms in cattle and sheep after eating the leaves as loss of appetite, nausea, and even vomiting, salivation, grinding of teeth, wind, colic, bloody diarrhœa, decrepitude, giddiness, loss of sensation, convulsions, and not seldom death.
Affected cows are stated to give bitter milk which has purgative effects (Pott).
The poisoning of two cows by H. viridis came under the notice of Cornevin. There was observed loss of appetite, diarrhœa, tenesmus, violent attempts to evacuate, which after 5 or 6 days resulted only in the expulsion of glareous blackish matter; to the end the pulse was slow and intermittent. The heart beats were weak, and after 5 or 6 beats there was a stop equal in duration to at least a beat and a half. A remarkable fact was the very gradual loss of condition, while the milk secretion was maintained until the last day. In one case death occurred after 12 days and in the other after 28 days.
REFERENCES.
63, 81, 130, 140, 170, 190, 203, 205, 213, 233, 254.
Larkspur (Delphinium Ajacis Reich.). In the United States of America certain species of Larkspur are exceedingly harmful to live stock, and it has been said that “with the exception of the Loco weeds there is probably no poisonous plant on the cattle ranges of the West that has caused such heavy losses to stockmen as has larkspur” (Far. Bul. 53, U. S. Dept. Agric.). D. Ajacis is the only British species, occurring in cornfields in Cambridgeshire, Sussex and elsewhere, and, like the Continental species D. Consolida, must be regarded as poisonous and fatal to cattle, while horses and sheep may also suffer. Sheep and goats, however, appear to resist the poison unless taken in considerable quantity. Wilcox fatally poisoned a yearling lamb within an hour of administering per os the extract from less than 1 oz. of the dried leaves of an American species. The seeds are the most dangerous part of the Larkspur, and should never be ground up with wheat should the two plants grow together. The seeds of D. Staphisagria are used in medicine.
Toxic Principle. The species D. Ajacis has been little studied, but D. Consolida and D. Staphisagria contain the alkaloids Delphinine (C31H49O7N), very poisonous and having a bitter taste; Delphisine (C31H49O7N), which is extremely poisonous; Delphinoidine (C42H68N2O7), which is poisonous; and Staphisagrine.
Symptoms. The seeds are stated to be emetic and purgative, and D. Consolida is stated by Pott to be an acute narcotic poison to horses and cattle. In general the symptoms appear to resemble those produced by Aconitum (p. 15). There is salivation, vomiting, colic, convulsions, and general paralysis (Müller).
REFERENCES.
16, 63, 93, 128, 130, 190, 203, 204, 205, 213, 233.
Monkshood (Aconitum Napellus L.). The extremely poisonous character of this plant has been recognised since ancient times, and it is mentioned by Pliny, Dioscorides, etc. It is not common in the wild state in Britain—chiefly occurring in some Welsh and one or two West of England counties—and is not very liable to cause poisoning of live stock in Britain. Cases of poisoning of horses, cattle, sheep and pigs have been recorded on the Continent, however (Cornevin), and cows died in Victoria. Linnæus says that it is fatal to cows and goats when they eat it fresh, but that when dried it does no harm to horses. Medical works record many cases of human poisoning, particularly in cases where the root has been mistaken for horse radish—from which, however, it markedly differs. The leaves at first taste insipid and then sharply burning; the root when fresh smells like the radish and has a slightly sweetish taste, which is succeeded by characteristic tingling of the tongue and a sensation of numbness in the mouth.
Toxic Principle. Monkshood is very poisonous, and though all parts are toxic the root is the most dangerous, and next the seeds and leaves. The plant seems to vary in toxicity with age and climate, being but slightly active when very young, most active just before flowering, and at the minimum of activity when the seeds ripen. The cultivated form is stated to be much less poisonous than the wild one. Drying removes a part of the toxic substance, and boiling removes most of it. The plant contains the toxic alkaloid Aconitine (C34H45NO11), and also Aconine (C25H39NO9). The root contains 0·17 to 0·28 per cent. of Aconitine, but the leaves and flowers less.
Symptoms. The chief symptoms are those of depression, and are manifested through the nervous system and the circulatory and respiratory organs. Tetanic symptoms are also present. There is loss of appetite, salivation, inflammation of the mucous membrane of the mouth and jaws, grinding of teeth, nausea and vomiting, great restlessness and colic; the animal groans and walks with an uncertain gait owing to bodily weakness, giddiness and paralysis of hind feet or of all limbs; there is also a notable slackening in the pulse, breathing becomes difficult, consciousness is lost and the pupils are dilated. Death ensues in most cases within a few hours, and after convulsions.
Kaufmann (quoted by Cornevin) observed in the horse champing of the jaws, salivation, fibrillous contraction of the muscles of the olecranon, then of the buttocks, then of the whole body. The intestinal pains were shown by the blows of the animal’s hind feet under and at the back of the belly. There was also observed an intense and painful contraction of the muscles in the inferior cervical region, the hyoid and the abdomen; an increased sensibility; repeated evacuations; at first congestion, then great paleness of the mucous membranes; diminution in the volume of the arteries; faint whinnyings at the moment of the contraction of the muscles of the neck, shoulders and stomach; muscular rigidity of the posterior limbs; uncertain gait; laboured breathing; and finally paralysis of motion, respiration and senses.
Lander in giving similar symptoms for the horse notices also choking movements of the œsophagus, eructation of frothy matter, dilatation of pupils and low temperature.
Kaufmann gives the poisonous doses of powdered root for the horse and dog as 13 to 14 oz. and ⅙ oz. respectively.
REFERENCES.
4, 16, 63, 78, 81, 128, 130, 153, 161, 170, 203, 205, 213, 233.
