MILK SICKNESS. “THE TREMBLES.”
Geographical distribution: timbered lands in the United States; different altitudes, and geological formations; on hills and wooded bottoms; known to Indians and pioneers; now unknown where formerly prevailed. Contagion: through milk; no specific microbe found in every case. Alleged causes: rhus; nickel; spirillum; bacillus. Prevails in dry seasons; contracted under night exposure; confined to given enclosures; to late summer and autumn. Not conveyed by contagion, indefinitely, as are plagues. Men show very varying susceptibility; young children may be relatively immune. Fatigue, debility, ill health, predispose. Exertion to fatigue rouses symptoms in animal affected. Cow in full milk eliminates toxins and does not show symptoms; the milk infects. Steers, bulls and heifers, show marked symptoms. Calves suffer through milk; swine through veal; dogs through pork; buzzard through dead dog. Incubation 8 to 12 days. Symptoms: tardy, lazy gait, drooping, anorexia, ardent thirst, inactive bowels and kidneys, milch cows when driven or excited, tremble and may suddenly die. Muscular debility, constant decubitus, complete apathy, neither evades nor resents injury. Bloodshot, fixed, glazed, unwinking eyes, pulse and breathing slow, temperature low, hebetude, torpor, coma; death 8th to 10th day. Sheep very prostrate. Calves tremble when sucking, vomit and perhaps die suddenly. Pigs and dogs vomit, and show costiveness, remarkable debility and weariness. Man is weary, languorous, weak, apathetic, loathes food, is nauseated, retches. No fever; but ardent thirst, tremulous tongue, mawkish breath, soft flabby belly, careless of own or family interests, forgetful of decency. Nausea, vomiting of blueish liquid, hebetude, inactive bowels, coma. Lesions: gastro-intestinal congestions; ingesta like hard balls of sawdust. Treatment: charcoal, mild laxatives, elm bark, egg nog, potassium permanganate. Prevention: clear timber land, let in sunshine, cultivate. Insects. Sterilize the milk.
This is an infectious disease which has been found enzoötic in certain unimproved, timbered lands of North Carolina, Georgia, Tennessee, Kentucky, W. Pennsylvania, Ohio, Michigan, Indiana and Illinois. Beach says it has never been reported on any of the Western prairies, at any point west of the Mississippi River, in New England, in the Canadas, in any islands, or in any part of the Old World. Altitude appears to have no effect in its production, nor geological formation; it has been found in the wooded mountains of the Blue Ridge of N. Carolina and Georgia (Kerr, Salmon, Phillips); in the hills of Pennsylvania and Kentucky; (Beach, Phillips); on timbered uplands (Phillips); and on the wooded bottoms of the Scioto and Miami in Ohio (Phillips, Schmidt); in the timbered bottom lands of the Wabash and White Rivers in Indiana (Phillips); and in the wooded bottoms (Beardsley), and Indian Grove in McLean, Co., Ill. (Beach). The constant conditions are the heavily timbered and virgin condition of the soil.
It was much more prevalent in the time of the early settlers, than it is to-day, many infecting localities having become salubrious in connection with the clearing away of the forests and cultivation of the soil. The disease was well known to the Indians and often proved disastrous to the pioneers, whole communities being swept off as recorded of Pigeon Creek, by Nicolay and Hay in their History of Abraham Lincoln. According to these writers it was “a malignant form of fever—attributed variously to malaria, and to the eating of poisonous herbs by the cattle—attacking cattle as well as human beings, attended with violent retching and a burning sensation in the stomach, and often terminating fatally on the third day.” Even in these early days settlers were loathe to acknowledge the existence of the infection on their lands, doubtless because it depreciated them, and to-day with a better knowledge of the necessary precautionary measures, it has literally disappeared in many places, so that it is now difficult to find a case.
Contagion. That the disease has been transmitted through the milk from animals to man and other animals has been too painfully evident from the first, but no specific microörganism has been found to be constantly present, capable of pure culture in artificial media and of causing the disease when transferred from such media to a new victim. Naturally all sorts of theories have been advanced, no one of which has been demonstrably proved. It has been attributed to eating of poison ivy (Rhus toxicodendron) by the cattle, as this plant was usually found on the infecting lands, but rhus is also common throughout New England and the Eastern States where milk sickness is unknown. It has been claimed that it was due to mineral agents, especially nickel, in the water but the mineral salts in the water are not removed by culture of the surface soil, which puts an end to milk sickness. Phillips (1876) claimed to have found the cause in an actively motile spirillum in the blood, but he had examined the blood of but one patient, and it has not been found in other patients by subsequent observers. Bitting found a bacillus but further research has not determined its constancy.
Beach furnishes a series of observations which should be useful in seeking to estimate the value of any theory propounded. 1st. Milk sickness is a disease of dry seasons. 2. In unusually dry seasons it is dangerous to leave domestic animals out over night in the localities where the disease is prevalent. 3d. It has never been considered dangerous for animals to pasture on such lands in the day time. 4th. Cattle in one field will habitually escape, and in another with apparently exactly the same conditions and the same flora they are attacked. 5th. The disease is unknown on the open prairies of the Western States, where the domestic animals are not allowed to remain over night in the timber belts. 6th. With occasional exceptions, it is a disease of late summer and autumn. The dangerous lots can, as a rule, be safely depastured in winter and spring. 7th. The pioneers found that they could protect their stock by keeping them corralled on a “tame” piece of land from before nightfall until the fogs and dews became dissipated on the following morning.
For the land to become “tame” it was only considered necessary to cut off the timber and let the sunshine act freely on the surface. Plowing and cultivation did not seem to be requisite in all cases.
A great drawback to research is the difficulty of securing cases to study. Many lots, formerly dangerous, are no longer so, and others still infecting are kept so secluded that casual cases cannot be found, without much expense for experimental animals. Again, owners do not care to depreciate their land by acknowledging that it is infecting. The experiment stations naturally enough look askance, on the proposal to institute expensive experiments on a disease which dies out when the soil is improved. Deadly as the disease is to the individual attacked (man or beast), it is not propagated indefinitely from non-milking subjects, by simple contact or proximity after the manner of plagues. It usually comes to an end by the death or recovery of the subject that has contracted it by consuming meat, milk, butter or cheese, the product of an infected animal. The demand for sanitary police measures is, therefore, less urgent. Different observers claim that cases occur in the large cities, through the consumption of meat, butter or cheese, sent from infected localities, but that the city physician fails to make a correct diagnosis. These must, however, be comparatively rare.
In addition to ingestion as a cause, certain accessory causes ought to be noted. Some men eat the infecting material with impunity, while others succumb to the deadly disease. As the observations have all been made in or near the infecting localities, individuals may be immune through a previous attack and recovery, or there may be a native immunity through unknown conditions. Young children often suffer less than adults, possibly because of the greater activity of their emunctories and consequent elimination of the toxic products and the comparative absence of exhausting or depressing conditions. Their purely animal food (milk) may exercise an influence, and this may assist in explaining the fact that certain adults appear to be refractory.
Fatigue, debility and ill health are said to predispose the system. Milk sickness attacks most violently those that have been subjected to overwork or severe exertion of any kind, especially in hot weather, those suffering from want of sleep (sitting up with the sick), those having a special cause of mental depression, those suffering from some illness—constipation, indigestion, malaria, etc.
Milch cows are probably more open to the attacks of the germ because their systems are reduced by simultaneous milking and breeding through a number of years. Exertion or fatigue has a potent influence in developing the symptoms, so that it is a common practice in the vicinity of infected localities to subject animals to a good run before purchasing. Paradoxically enough the infected milch cow which is distributing the infecting element freely in her dairy products usually shows, in herself, no distinct symptoms of the disease. If she is dry or farrow she suffers like any other animal, but if in full milk, the toxins, and even the hypothetical microbe, seem to escape in that secretion, which proves highly poisonous to other animals, while the cow retains her spirits, vigor and outward appearance of health. Steers, bulls and heifers, on the other hand, show violent symptoms.
Calves suffer so long as they suck the milk. The dead calf is eaten by swine, which suffer in their turn, and the dog contracts the disease by eating one of these animals, or by taking infected milk or cheese. The buzzard eats the dead dog and dies as the result.
Incubation is from 8 to 12 days, though it may be reduced to two. (Beach.)
Symptoms. In the domestic animals the first indication of illness is a lazy, tardy disposition, The subject stands apart from the herd, with drooping head and ears, listless, indifferent to all around him, and often without appetite; or, in cattle or sheep, rumination. There is usually extreme thirst, but without correspondingly free urination or defecation. Peristalsis is virtually abolished and nothing whatever passes from the bowels. The patient is likely to be found lying down and it is difficult to get him up, and when raised he moves stiffly and with reluctance.
In milking cows there may be no symptoms until the animal is excited or fatigued by violent or continued exercise, as a hard run, or a drive of four or five miles. This developes the tremors alike in milch cows and in the mild cases in dry cattle or sheep. The subject stands still and trembles in a striking way, the action resembling the muscular contractions seen after the removal of the hide in an animal newly killed. The head and ears are drooped, movements are uncertain and stiff, and the animal may even drop dead on the spot.
As the disease advances the muscular debility becomes so great that the animal lies down if possible, and if once down he seldom rises again. The decubitus is extended, the head being stretched on the ground. There is a most complete apathy, the subject showing no fear, no apprehension, no disposition to escape or resent injury. The wildest or most timid steer can be freely handled, and there is no disposition to flight or retaliation. The eyes are bloodshot and become fixed and glazed, winking ceases, the breathing is slow, pulse infrequent, and temperature often subnormal. The extremities and surface of the body are cool, the muzzle dry, the coat usually stares, the apathy merges into a complete hebetude, torpor and coma, in which condition the animal often dies on the eighth or tenth day. Violent exercise precipitates the death at once. Recoveries are infrequent and attended by no critical discharge from bowels or kidneys, only by a slow, at first almost imperceptible, resumption of natural action.
The milder cases, those that show no appreciable symptom when at rest, are seized with trembling or rigor when made to undergo the slightest exertion; they appear haggard, stupid and spiritless, drag their limbs slowly and stiffly and quickly stop from pure weariness and debility.
The prostration is even more marked in sheep, which often seem unable to rise, or lack the nervous energy to do so.
Calves tremble while sucking, and will sometimes leave the teat, vomit the contents of the stomach, fall down and perish.
In Vomiting Animals (pig, dog,) emesis usually occurs, and torpor of the bowels or obstinate constipation is present. Pigs burrow under the litter and are driven out with difficulty, and dogs when called on to follow, do so reluctantly, slowly and stiffly and fail to keep pace with their master (“the Slows”).
In all animals alike active or continued exertion rouses or intensifies the symptoms.
In man there is at first extreme langour, weariness and weakness, the patient cannot be troubled to move, he loses appetite, loathes food, and soon has nausea and retching—often from the first. There is no chill, rigor nor violent headache as in other fevers; but insatiable thirst; large, flabby, tremulous, moist tongue, coated a dirty white; cold nose, ears and general surface; dry skin; sweet, mawkish or offensive breath; flat, flabby empty belly; without peristalsis or defecation. Respiration becomes very slow, pulse weak and compressible, heart action tumultuous and labored, temperature often below normal, and though sometimes 99° or 100° F., never higher. The patient takes to bed in four or five days, or, after exertion or fatigue, in a few hours becomes profoundly apathetic, expresses no concern for his business, his own future or that of his family, is intolerant of bed clothes or other covering and utterly oblivious of the demands of decency. Nausea continues, but retching becomes weaker, and comparatively ineffective, or brings up a little liquid which has been compared to blueing water of the laundry. The apathy merges into a state of hebetude and this into coma, with fixed, glazed eyes, absence of all winking, and insensibility to irritants and death takes place quietly without a moan or struggle.
Recovery is slow, and improvement for a time is almost imperceptible. In some cases there remains a nervous atony, and in man, a lack of mental and bodily vigor, and a disposition to relapse under exposure to intense heat or fatigue has been noted, but in many cases recovery is complete and permanent without lasting weakness.
Lesions. Both in man and animals, congestions of the gastric and intestinal mucosæ have been noted, usually with a dark firm condition of the membrane, but in some cases with capillary stasis, and sloughing. Beach never saw indication of tenderness in the abdomen or elsewhere, nor did he ever find blood nor stercoraceous matter in the vomited material. The contents of stomach (paunch in cattle) and bowels formed hard balls like cemented sawdust, firmly adherent to the dry mucosa.
Treatment and Prevention. Treatment by the Indians consisted in giving large doses of powdered charcoal suspended in milk. The early physicians attempted to open the bowels by calomel and jalap, olive oil, magnesia citrate, and even croton oil, but the last generally with fatal results. Milder and hardly less effective treatment consisted in large doses of elm bark. Beach believed he got better results with quinine and egg nog. It might be suggested to try such antiseptics as potassium permanganate, peristaltic stimulants like eserine or pilocarpin, as an eliminating agent pure water or weak diuretics, and nerve stimulants nitroglycerine or ammoniacal preparations.
Prophylaxis. The time-honored resort of clearing the timber and brush land so as to let the sun act freely on the soil, and the putting in of cultivated crops, is proved reliable and permanent. The other precautions in use are valuable in protecting the herd, but lack the merit of thoroughness and permanence and thus fail to strike at the root of the trouble. They are: 1st. the exclusion of domestic animals from the infected woods in late summer and autumn and in very dry seasons; and 2d. the exclusion of stock from such pastures from before nightfall until after the dews have evaporated on the following morning.
The danger which attends on passing the night in the forest, strongly suggests the intervention for the transfer of the poison of some nocturnal animal, perhaps a night-flying insect, like the anopheles, which transmits the plasmodium of malaria. If the germ and its intermediate bearer (if any) were demonstrated, probably other and simpler means of prevention could be adopted.
The fact that the propagation of the disease is not constant and wide spreading, like a genuine plague, lessens the urgency for a rigid sanitary police, yet animals kept on such infected farms, should be tested by long or vigorous driving before they are killed for food, and all milk devoted to the production of butter and cheese should be Pasteurized or sterilized before use. It might well be questioned whether the clearing and exposure of infecting places should not be undertaken by the state as a sanitary measure.
In view of the fact that a milch cow may not show symptoms of the disease, and yet yield deadly milk, and considering that the owner cannot always tell whether she has been in the infecting woods, or having been in, whether she is infected, it becomes an important public health question whether such a source of deadly disease should be perpetuated, where human food is open to contamination.