Special Report on Diseases of Cattle Part 9

This plant, growing in wet places by ditches and along creeks, is the most poisonous of North American plants. The root is the poisonous part, and cattle generally get it when it is plowed up or washed out by high water.

Sometimes they pull it up, for the plant occasionally grows out into ditches so that the whole plant will be taken in grazing. The most marked symptoms of Cicuta poisoning are the violent convulsions, which remind one of the effect of strychnin.

_Treatment._--Little can be done in the way of treatment. The logical thing is to attempt to control the convulsions by means of morphia, but in view of the fact that the stomach can not be emptied, the prognosis is not good, and most cases die.

LARKSPURS.

The larkspurs are a source of heavy loss to cattle owners in the higher ranges of the West. There are a number of species, growing at alt.i.tudes from 4,000 feet to timber line, and all are poisonous. A few cases of poisoning by larkspurs have been reported in the eastern United States, but most of the losses are confined to the West, both because larkspurs grow there in greater profusion and because cattle are grazed in that region on the open ranges. The losses are confined to cattle, for sheep and horses can graze on larkspur with no resulting harm. Most of the larkspur losses occur in the spring and early summer, as the plants lose their toxicity after maturing.

_Symptoms._--Larkspur poisoning is accompanied by a definite line of symptoms. In range animals the first symptom noted is generally the sudden falling of the animal and consequent inability to rise. After a while it may rise, only to fall again. This may happen repeatedly. In severe cases the animal lies p.r.o.ne and exhibits nausea, accompanied by vomiting. It dies of respiratory paralysis, death many times being hastened by the asphyxia following the vomiting.

_Treatment._--The animal, if found down, should be turned so that its head is uphill in order to relieve the lungs. Many cases will recover with no further treatment. Nearly all cases will recover if a hypodermic injection is given immediately of physostigmin salicylate 1 grain, pilocarpin hydrochlorid 2 grains, strychnin sulphate 1/2 grain.

LOCO.

The loco plants have caused especially heavy losses of cattle, horses, and sheep. They grow in the semiarid regions of the West and sometimes in great luxuriance. The best known are the "blue loco," the "woolly loco" or "purple loco," and the "white loco" or "rattle-weed." The blue loco is common in parts of New Mexico, Arizona, and Utah. It affects both horses and cattle. The purple loco, _Astragalus mollissimus_, is common in Texas and the adjoining States and extends north as far as Nebraska and Colorado.

It is especially destructive to horses. The white loco, _Oxytropis lamberti_, is still more widely distributed, being found in the plains region from Alaska to Mexico and west of the Rocky Mountains to central Utah. The white loco is much more important than the purple loco, for it affects not only horses but cattle and sheep. These plants belong to the pea family, and there are a number of other species of this family that are loco plants and produce the same symptoms.

_Symptoms._--Loco poisoning is a chronic condition and symptoms are shown only after somewhat prolonged feeding. The condition is one of c.u.mulative poisoning, and animals sometimes decline very rapidly after the first symptoms appear. In many cases animals acquire a habit of eating loco and prefer it to any other feed. The poison affects the central nervous system.

There is a lack of muscular coordination and the animal performs very erratic movements. In the later stages the animal becomes emaciated and eventually dies of starvation.

_Treatment._--Locoed animals are badly constipated, and it is important that this condition should be remedied at the start. Any purgative can be used, but Epsom salt has been found especially effective. If locoed animals can be turned into a field of alfalfa, a large proportion of them will recover with no further treatment. Recovery may be aided by giving cattle, hypodermically, daily doses of three-twentieths to four-twentieths of a grain of strychnin. By this treatment cattle can be cured and put in condition for market.

WHITE SNAKEROOT (EUPATORIUM URTICaeFOLIUM).

White snakeroot, frequently known as "rich weed," is a plant growing in great abundance in some of the eastern and central regions of the United States. It is particularly abundant in parts of Ohio, Indiana, and Illinois, and in western North Carolina. It is responsible for most, if not all, of the cases of a disease which is commonly known as "milk sickness."

_Symptoms._--The animals are constipated, sometimes have b.l.o.o.d.y feces, become weak, and exhibit muscular trembling. This trembling is very characteristic, so that the disease is sometimes known as "the trembles."

_Remedy._--There are no remedies which will work very efficiently. It is desirable to give the animals purgatives like Epsom salt and, of course, to remove them from fields where this plant is abundant.

RAYLESS GOLDENROD (ISOCOMA WRIGHTII).

The rayless goldenrod is a plant growing in especial abundance in parts of the Pecos Valley in New Mexico and Arizona, and there produces a disease so much like that produced in the East by white snakeroot that it is sometimes called milk sickness. More generally this disease goes under the name of "alkali disease." The plant has produced heavy losses in the regions where it grows abundantly.

_Symptoms._--The symptoms are much like those produced by the white snakeroot. The animals are constipated, sometimes have b.l.o.o.d.y feces, become weak, and exhibit muscular trembling. There is good reason to think, too, that the milk of cows eating this plant is more or less injurious.

_Treatment._--A purgative like Epsom salt will aid an animal in recovering, but most important is to remove the cattle from pastures where the plant is abundant and give them an abundance of good forage. Under such conditions they are almost certain to recover.

MILKWEEDS.

Many of the milkweeds have long been known to have more or less poisonous properties. Within the last few years it has been discovered that certain of the milkweeds going under the popular name of whorled milkweeds are especially toxic. There are at least four species of whorled milkweeds, but two of them are particularly important from the standpoint of people handling livestock. One, known scientifically as _Asclepias galioides_, is harmful in Colorado, Utah, Arizona, and New Mexico, while another, known as _Asclepias mexicana_, has produced losses, especially in California and Nevada. These whorled milkweeds are distasteful to all animals and are eaten only when the stock is closely confined to pastures where there is little else in the way of forage.

_Symptoms._--The most prominent symptoms are weakness, producing staggering, and this is followed in acute cases by violent spasms.

_Treatment._--There is no treatment which will effectively antidote the effect of the poison. In practically all cases, however, poisoning may be avoided if care is taken to prevent animals from being closely confined where this plant is abundant, as they never eat the plant by choice.

CHERRY.

In the leaves of the cherries more or less hydrocyanic acid is produced, and when these leaves are eaten in any considerable quant.i.ty cases of poisoning are likely to arise. It is popularly supposed that these cases arise from eating wilted cherry leaves, but there is every reason to think that the fresh leaves will produce the same results. These cases are easily prevented, because no harm results from eating a small quant.i.ty of the leaves, and if the fact is recognized that poisoning may result from eating a large quant.i.ty, it is not difficult to care for the animals so as to prevent poisoning.

ERGOTISM.

The poisonous effects of ergot (Pls. V, VI) appear chiefly in the winter and spring of the year and among cattle. It is developed among gra.s.ses grown on rich soil in hot, damp seasons. Rye seems more liable to ergot than any of our other crops. Of the gra.s.ses which enter into the composition of hay, bluegra.s.s is the most likely to become affected. Ergot may also affect redtop, oats, gra.s.ses, and grains. On the plant the fungus manifests itself on the seeds, where it is easily recognized when the hay is examined in the mow. The ergotized seeds are several times larger than the natural seeds--hard, black, and generally curved in shape.

The effect of the protracted use of ergot in the feed is pretty well understood to be that of producing a degeneration and obstruction of the smaller arterial branches. The result is to shut off the blood supply to the distal parts of the body, where the circulation is weakest, and thus to produce a mummification or dry gangrene of the extremities, as the ears, tail, feet, etc. Cattle seem to be more susceptible than other animals to the influence of ergot, possibly on account of the slowness of the heart's action. When the effect of the poison has become sufficient to entirely arrest the circulation in any part, the structures soon die. The disorder manifests itself as lameness in one or more limbs; swelling about the ankle which may result in only a small slough or the loss of a toe, but it may circ.u.mscribe the limb at any point below the knee or hock by an indented ring below which the tissues become dead. The indentation soon changes to a crack, which extends completely around the limb, forming the line of separation between the dead and living structures. The crack deepens till the parts below drop off without loss of blood, and frequently with very little pus. Ergot may cause serious irritation of the digestive tract, or by acting upon the nervous system it may cause lethargy or paralysis. It also operates to cause contraction of the uterus, and may thus cause abortion.

_Treatment._--Regarding the treatment, change of feed and local antiseptics are, of course, indicated. The former may be useful as a preventive, but when the symptoms have appeared the animal is necessarily so completely saturated that recovery is likely to be tedious. Tannin may be given internally in doses of one-half dram twice daily for a few days to neutralize the unabsorbed alkaloids of the ergot. At the same time give castor oil. To dilate the blood vessels give chloral hydrate. Bathe the affected parts with hot water. If sloughing has gone far, amputation must be resorted to.

OTHER POISONOUS FUNGI.

Many other fungi poison herbivora. In some instances, however, where fungi are blamed for causing disease their presence on the feedstuff or herbage is but coincidental with some other and more potent disease-producing factor. For example, if the conditions are favorable to the growth of fungi they are also favorable to the growth of bacteria, and bacteria may produce poisons in feeds. In general it may be said that any feed that is moldy, musty, or putrid is possibly dangerous. Silage, properly cured, does not belong to this cla.s.s, because the curing of silage is not a bacterial process. But spoiled silage and silage matted with mold is dangerous and should not be fed.

POISONING BY ANIMAL PRODUCTS.

SNAKE BITES.

The poison contained in the tooth glands of certain venomous reptiles, particularly some of the snakes, which is injected into or under the skin of an animal bitten by the reptile, is a very powerful agent. It is likely to produce a serious local irritation, and in the case of the more poisonous snakes serious const.i.tutional disturbances, even to causing death, which it may do in either of two ways: First, when very strong, by exerting a narcotic influence similar to that of some of the powerful poisons, checking heart action. Second, by diffused inflammation of the areolar tissue, gangrene, and extensive sloughing.

_Symptoms._--The symptoms of snake bite are a local swelling caused by an intense local inflammation, p.r.i.c.ks showing where the fangs penetrated, depression, weakness, feeble pulse, difficult breathing, bluish discoloration of the visible mucous membranes, stupor, or convulsions. If the poison is not powerful or plentiful enough to produce death, it is, at any rate, likely to cause severe local abscesses or sloughs.

_Treatment._--The treatment may be divided into local and general. Locally every effort should be made to prevent absorption of the poison. If discovered at once the bitten part had better be excised. If that is impracticable and a ligature can be applied, as in the case of a bite to one of the limbs, no time should be lost in applying it above the injury.

It should be made sufficiently tight to so far as possible arrest circulation in the bitten part. The wound should be freely incised, so that it will bleed freely, and the poison should be extracted by cupping, or pressed out by squeezing with the fingers. Permanganate of pota.s.sium in 5 per cent solution should be applied to and injected into the wound. The depressing effect of the poison on the general system should be counteracted by hypodermic injections of strychnin, or by liberal drenching with stimulants, such as coffee, digitalis, or the aromatic spirits or carbonate of ammonia. In animal practice the alcoholic stimulants and local treatment above described are likely to meet with best success. A special ant.i.toxin for use in treating snake bite is now prepared and may be had from the leading druggists. It is quite effective if used promptly.

WASP AND BEE STINGS.

Wasps and bees secrete a poisonous substance which they are able to insert through the skin of an animal by the aid of their sharp stings. This poison is a severe local irritant and may even cause local gangrene. It also has a depressing effect upon the central nervous system and destroys the red-blood corpuscles. To produce these general effects it must be introduced in very large quant.i.ties, as when an animal is stung by a swarm of bees or wasps.

_Treatment._--The treatment is to wash the parts with diluted ammonia or permanganate of pota.s.sium solution and to give stimulants internally. If there is so much swelling about the head and nostrils as to interfere with breathing, tracheotomy may be necessary.

POISONING WITH SPANISH FLY.

Spanish fly, in the form of powdered cantharides, may be given in an overdose, or when applied as a blister to too large a surface of skin enough may be absorbed to poison. If given by the mouth, it causes severe irritation of the gastrointestinal tract, shown by salivation, sore throat, colic, b.l.o.o.d.y diarrhea, etc. It also produces, whether given by the mouth or absorbed through the skin, irritation of the urinary tract, as shown by frequent and painful urination. If death results, it is due to respiratory paralysis.

_Treatment._--Give protectives and the white of egg, with opium. Do not give oils or alcohol.