EUPHORBIACEÆ.
Spurges (Euphorbia sp.). Many species of Spurge must be regarded as acrid, purgative, and poisonous. Live stock are not likely to touch them, owing to the acrid effect of the milky juice on the mouth.
The Caper Spurge (E. Lathyris L.) contains an acrid, emetic, and highly purgative milky juice, and the fruits have commonly been employed by country folk as a purge, and also as a pickle, though they are dangerous and should not be so used. Pratt records a case in which five women ate the pickled fruits with boiled mutton, and all suffered severe pain and burning in the stomach, and showed other symptoms attendant on irritant poisoning—and though all recovered the illness was severe. Used in this manner, indeed, they have given rise to serious cases of human poisoning. Only very young animals are said to eat it, but cattle in the United States are said to be “quite resistant to its influence, but they are sometimes overcome.” According to Chesnut goats eat this plant extensively, and it is said that their milk then possesses all the venomous properties.
Petty Spurge (E. Peplus L.) is somewhat similar to the Caper Spurge in poisonous properties, and fatal poisoning has occurred through a boy eating it.
Sun Spurge (E. Helioscopia L.) is similarly poisonous to the preceding species. It has caused fatal poisoning to a boy who ate it. In Germany cows were poisoned through pasturing in stubble in which the plant was growing, but there were no deaths.
Toxic Principles. The milky juice of these spurges contains highly acrid poisonous substances, which have not been individually and fully investigated. Drying may reduce the toxicity but does not eliminate it.
Symptoms. As regards E. Lathyris Chesnut says that on the skin the juice causes redness, itching, pimples, and sometimes gangrene. The seeds when eaten inflame the mouth and stomach, cause vomiting and intense diarrhœa, and if the illness is serious, nervous disorders, unconsciousness, collapse, and death.
The Euphorbias have an acrid effect on the mouth, and severe poisoning may follow their use as aperients—burning mouth, swelling tongue, stomach pains, cold skin, vertigo, fainting or syncope, and even death in two or three days (Esser).
Similar symptoms are given by Cornevin, who states that the Euphorbias have an irritating effect on the mucous membrane, especially at the back of the mouth. In from three quarters of an hour to two hours after eating the plant, or even longer, there is painful vomiting, followed by diarrhœic evacuations, with a lowering of the temperature. If the quantity ingested has been sufficient there appear also nervous symptoms, vertigo, delirium, muscular tremors, and respiratory and circulatory troubles which disappear after abundant sweating if the poisoning is not fatal. If it is fatal the symptoms of superpurgation and enteritis predominate, but are accompanied by nervous symptoms and circulatory disorders.
Müller gives in addition loss of appetite, piteous whining (in goats), groaning, colic and tympanites; and Pott, bloating, fever, palpitation of the heart, and loss of consciousness. Cows gave a reddish or sharp-tasting milk. Milk of affected goats caused diarrhœa human beings.
REFERENCES.
[19], [52], [53], [73], [81], [82], [130], [141], [190], [213], [216].
Dog’s Mercury (Mercurialis perennis L.) and Annual Mercury (M. annua L.). These two species may be taken together as they have similar poisonous properties, and closely resemble one another, though the former is a perennial and the latter an annual. The plants have a somewhat unpleasant odour, and live stock are not likely to take them unless pressed for readily available green food. The loss of one cow and severe illness of four others was recorded by Blackhurst in the Veterinary Journal in 1896; Güssow mentioned the loss of cows in the Farmer and Stock Breeder Yearbook, 1907; the loss of horses fed on herbage cut from a hedge and containing M. perennis was recorded in the Journal of the Royal Agricultural Society in 1898; the loss of sheep was recorded by Henslow. As regards man, Ray records a case in which a family of five persons suffered severely from eating M. annua fried with bacon. Fishermen ate it with soup and all were seriously ill an hour later, with symptoms of irritant narcotic poisoning; two children died the next day. Cornevin saw M. annua used, after boiling, as a food for pigs, without ill consequences, in the east of France. This is believed to be due to the poison being volatile and destroyed by heat or boiling; hence in hay the plant is harmless, though Pott says that even in hay stock avoid it.
Toxic Principle. The poisonous properties are said to be due to Mercurialine, Oil of Euphorbia, a volatile toxic alkaloid. Esser states that the stem and leaves of M. annua contain Trimethylamine, which may perhaps be a decomposition product of Choline, a poisonous base.
Symptoms. Both plants are emetic and dangerously purgative, causing irritant and narcotic symptoms. Veterinary observation has shown that the poison is cumulative, and that it is usually after the weed has formed part of the food for 7, 8, or 10 days that symptoms first appear. In the case recorded by Blackhurst (see above) the cows suffered from inflammation of the digestive tract, with severe purging and loss of blood. The secretion of milk entirely stopped. One cow died, but three recovered in about four days. The fifth was not convalescent for three weeks and then had a permanently curved and injured neck, the muscles being subsequently found rich in fibrous tissue, and the last three joints partially anchylosed. Rabbits were tested by feeding two on the leaves, two on the stems and roots, and two on the ground seeds mixed with oatmeal; the first two were unaffected, but the other four died in a few hours, showing drowsiness and suffering, while the post-mortem showed gastritis.
The digestive and urinary tracts are affected. There is indigestion with slight bloating, then colic of varying intensity, and at first diarrhœa which may give place later to constipation; hæmaturia; micturition is frequent, painful, and the urine is blackish and bloody; dullness, weakness, loss of appetite and refusal of food; the heart beats very strongly, the pulse is rapid, and the mucous membrane of the eye is reddish-yellow in colour. There is no modification of respiration (Cornevin).
According to Müller, however, the symptoms at first include constipation and later severe and bloody diarrhœa.
In cattle Pott states that M. annua causes inflammation of the stomach and intestines, bloody urine, paralysis of bladder, fœtid diarrhœa, abortion, and bluish coloured milk deficient in fat. Müller states that there is occasionally blood in the milk. According to Lander there is in cows excessive bloody purgation, cessation of lactation, temperature 105° F., pulse 90, and increased respiration. The illness is protracted over several weeks, the animals being comatose after the first symptoms.
REFERENCES.
[73], [81], [112], [130], [146], [170], [190], [205], [213], [255].
Box (Buxus sempervirens L.). Farm live-stock may occasionally have the opportunity of browsing on box, or clippings may be thrown to them with other green herbage from gardens. Care should be taken that clippings are otherwise disposed of. All parts of the plant are bitter and have been proved to be poisonous. The bitter taste tends to prevent animals eating sufficient of the plant to cause serious injury. Pigs have died a day after eating the leaves. Horses also were killed by eating 750 grammes (1·6 lb.) of the foliage.
Toxic Principles. Fauré found in the bark and leaves of box the toxic alkaloid Buxine, but it was believed that there were other toxic substances, since analysis showed the leaves to be less rich in Buxine than the bark, while they are three times as active. Other substances occurring in box are Parabuxine, Buxinidine, and Parabuxinidine.
Symptoms. Small amounts have an emetic and purgative action; with average amounts, there are, in addition, nervous symptoms, lameness, muscular tremors, vertigo, then a period of coma. Large amounts cause death with intense abdominal pains, dysenteric flux, tenesmus, convulsions, respiratory and circulatory troubles.
Pigs are chiefly affected after eating the leaves, exhibiting great thirst, uncertain gait and delirium, while death occurs within twenty-four hours.
Pott gives the general symptoms as sickness, diarrhœa, giddiness, stupefaction, convulsive movements, and colic.
REFERENCES.