Part 49

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.

VARIOLA: POX.

Definition: Structure of lesion. Nomenclature. History, smallpox, sheeppox, cowpox, horsepox. Animals susceptible: Man, sheep, cow, goat, horse, pig, dog, buffalo, camel, monkey. Microbiology: A pure contagium, particulate contagium, cocci, sporidium vaccinale. Horsepox: Early history, means of infection. Symptoms: Vesicles on lips, on heels, concretions, treatment. Cowpox: Relation to horsepox. Causes. Relation to smallpox. Observations of Ceely, Fletcher, Thiele, Klein, Martin, Reiter, Chauveau, influence of vaccination, of spring parturitions, of infected stables. Symptoms: Incubation, seat and nature of vesicle, inoculations for vaccine. Diagnosis from aphthous fever, rinderpest, eruption of mastfeeding, false cowpox, streptococcus eruption. Duration. Course. Prognosis. Treatment. Sheeppox: Synonyms. Definition. Pathogenesis: Sheep, goat, ox, dog, pig, horse. Forms: Discrete, confluent, hæmorrhagic. Distribution. Causes. Contagion; extends on air; experiments on blood; wool, hides, litter, buildings, yard, parks, railway cars, boats, clothes, manure, wine, milk, men, dogs, cats, birds, vermin, flies. Receptivity. Overcrowding, filth, starvation, neglect, wars, commerce. Recovered sheep. Disinfectants. Incubation 4 to 7 days; conditions affecting. Symptoms: Hyperthermia, general disorders, rigors, anorexia, skin blush on parts devoid of wool, red points, papules, vesicles, pustules, desiccation. Successive crops. On eye, nasal mucosa, mouth, pharynx, intestines, lungs. Confluent cases. Lesions. Prognosis. Mortality. Depreciation. Treatment. Prevention: By segregation, slaughter and disinfection; by ovination. Technique of ovination. Resulting immunity. Sheeppox in Goat: Danger of infection to sheep. Goatpox. Swinepox: From man, sheep, goat. Symptoms. Forms: Discrete, confluent. Susceptibility of young. Treatment. Prevention. Dogpox: From man; from sheep. Other eruptions in dog. Symptoms: Fever, flushed skin, red points, papules, vesicles, pustules. Discrete. Confluent. Treatment. Prevention of infection of man and sheep.

By the generic name Variola is understood a febrile malady attended by a characteristic eruption on the skin, at first papular, then becoming vesicular and finally pustular. The structure of the vesicle is so characteristic that it may be taken to indicate the variolous eruption as found in man and a variety of the domestic animals. The first indication of the lesion is the appearance on the skin of fine points of congestion like fleabites. This is followed by active diapedesis and proliferation of cells in the papillary layer and rete mucosum, constituting the nodule or pimple stage. In smallpox this is so firm and definitely outlined that it has been compared to the presence of a shot in the skin. As the proliferation of cells increases these form in separate clusters or groups, isolated from each other by septa or walls largely made up of the epidermic cells. In the next stage, therefore, when exudation takes place the lymph accumulates in the spaces occupied by the clusters of growing cells, and is found in a series of chambers more or less perfectly separated from each other, so that to evacuate the whole vesicle, each minute sac must be punctured independently. The vesicles thus differ from others caused by ordinary irritants in that each is chambered, instead of forming one common undivided sac, which may be emptied by a single puncture. In the next stage, when suppuration ensues, the septa usually undergo liquefaction, so that the liquid occupies one individed cavity in each pustule. For this reason the central depression seen in the larger vesicles (cowpox) in their early stage tends to disappear in the pustule. It may reappear later in the resulting scab. Desiccation, scabbing and desquamation complete the course of the affection, a distinct pit being left as a result of the destruction of the superficial layer of the dermis.

Nomenclature. The term variola is believed to come from the Latin varius (variegated, spotted) and pox from the Saxon pock (pouch). The specific names, drawn from these tongues sustain this view: As, variolæ vaccinæ, cowpox, kine-pox; variolæ equinæ, horsepox; variolæ ovinæ, sheeppox; variolæ caprinæ, goatpox; variolæ suillæ, swine pox; variolæ caninæ, dog pox. The term smallpox, (petite verole) is deduced from the small size of the vesicle as compared with that of cowpox, just as the same has originated the term smallpox in sheep.

History. Variola has undoubtedly existed from very ancient times. Moore found it referred to in Chinese records of 1122 years before Christ, but it was only clearly described early in the tenth century by Rhazes an Arabian physician. Gregory, however, found the name variola in Latin manuscripts in the British Museum of a much earlier date. The early epidemics of small pox have usually extended from the east, and the disposition has been to refer its origin to the crowded communities of central Asia, but nothing is certainly known as to such origin and the lack of definite recognition and description cannot be taken as implying that the disease did not exist. The extension of small pox to America in 1520 was distinctly traced to a sick negro slave landed in Mexico, and the way in which it swept the continent killing the Indians by tens of thousands, speaks strongly for its prior absence and the extraordinary susceptibility of the hitherto unaffected Indian races.

The variolæ of animals are not recorded until later, the mildness of the forms attacking cattle and horses, and the lack of close observation of the diseases of sheep furnishing a reasonable explanation. We must pass over as uncertain the lues ovium of Thomas Wallsingham, (Historia Anglicana), imported in a rotten Spanish ewe in 1274, and which prevailed for 25 years destroying nearly all the sheep of the kingdom, also the reference to the “pockes” of sheep in Chaucer’s “Pardoners’ tale” as highly uncertain. Laurent Joubert in his work on the “peste” mentions sheep pox as prevailing in 1567, and Rabelais speaks of it as prevailing in France in 1578. It prevailed in Padua in 1649, in Venice in 1664, 1672, and 1674 (Bottani), in Italy in 1690 (Ramazini), in Germany in 1687–8 (Stegman), in England in 1711, in Hungary in 1712, in France, Italy, etc., in 1714 (Kanold), in Venice and Bohemia in 1719 (Bottani), in Saxony in 1720, in Venice and France in 1723–24 (Bottani, Astruc), in Thuringia in 1725, in Siberia in 1771 (Pallas), and in Persia generally at the beginning of the 19th century (Bruce). Great Britian, long protected by her insular position, was infected by sheep from Germany in 1847 and again in 1862. Under ovination the first invasion prevailed for four years causing wide spread destruction; under strict separation based on thermometry, the second lasted but four months.

Cowpox has existed in England for centuries, but it has only attracted general attention since the introduction of vaccination by Jenner in 1796. Horsepox has existed concurrently with cowpox, the infection being habitually transferred by the hands of the milkers from horse to cow and vice versa. Jenner found it so common in the Valley of Gloucester, that he considered it as the habitual source of cowpox. Sacco recognized it at the beginning of the 19th century, Hertwig in Berlin in 1830, Röll in Vienna in 1855, and Bouley and others later in different parts of Europe.

Animals Susceptible. Variola in some form affects man, sheep, cattle, horses, goats, pigs, dogs, buffaloes, camels and monkeys.

Microbiology and Infection. It has long been well established that variola is due to contagion alone. The habitual dread of contact with a smallpox patient, shows the general appreciation of the danger of contagion, and the many epidemics, started by the introduction of a smallpox patient and thereafter spreading from that as a centre, together with the long continued immunity of certain insular or trans-oceanic countries illustrate this. One of the most striking examples is the immemorial immunity of the New World until the landing of the variolous slave in Mexico in 1520, and the immediate, rapid and destructive spread of the disease among the native tribes. Sheeppox offers a no less striking example. Prevailing for centuries in Asia and Europe, its extension to a new district was always the manifest result of the movement of infected sheep; England remained immune until her first invasion in 1847, and the second in 1862, in both cases the source was easily traced, and the disease completely extinguished by the destruction of the infection in its circumscribed area; the more distant sheep raising countries, America, North and South, Australia, Tasmania, New Zealand, South Africa, in the absence of importation of infected sheep remain free to the present time. For horsepox and cowpox the demonstration is more difficult as limited outbreaks, have occurred at intervals in different localities, traceable more or less clearly to infection from vaccinated persons, yet often mistakenly attributed to spontaneous developments of the disease. Before the days of Jenner however it prevailed habitually in certain dairying districts (Gloucestershire), and I can point to localities in New York, in which the infection is manifestly laid up in the stables, and the disease develops yearly in the heifers coming into milk for the first time and in newly purchased cows, that have not been previously exposed.

The contagion varies greatly in force in the different forms of variola, the milder horsepox or cowpox, requiring actual contact (inoculation) while in smallpox and sheeppox, infection may take place at some distance from the patient (in sheep over 200 yards).

A particulate infecting material was demonstrated by Chauveau, who filtered the virus and inoculated the filtered liquid without effect, while the solids retained on the filter invariably produced the disease.

The identity of the microbe of variola has been much discussed. Guttmann and Grigorjew found in the lymph a coccus (Staphylococcus albus variolæ), Ruete a very motile diplococcus, and others streptococcus, but in cutaneous lesions it is very difficult to exclude such elements. Pfeiffer, Guarnieri, Van der Loeff, Wasielewski and others have drawn attention to small protoplasmic bodies (manifestly protozoa) found in the vaccine lymph, and which appear to be the infecting agents. Wasielewski cultivated these on a rabbit’s cornea to the 48th generation, and from the last successfully inoculated a calf and several children.