Part 87

d. Injection of Blood from Bodies of the Ticks. In view of the difficulty of shipping infected blood without danger of contamination or sepsis, and the occasional accidents that happen to animals injected with such blood outside of the infected area, attempts have been made with dried blood, or that charged with antiseptics (calcium oxalate), or that had been frozen, but in every instance the virulence of the pyroplasma was destroyed. Dalrymple and Dodson availed of the blood drawn by mature ticks, which, in their blood-gorged condition, were shipped to the points where the injections were to be made. The mature ticks charged with blood were taken from infected indigenous cattle, and at once shipped. On their arrival they were washed externally with a mercuric chloride solution (1:1000) to destroy any adherent saprophytic or other bacteria, mashed in a sterilized mortar, with a few cubic centimeters of boiled water and the fluid portion drawn off and injected subcutem, into the animal to be protected. From 3 to 12 mature female ticks were used for each animal. The results were the same, only milder than when the blood of the indigenous animal was used direct, and the subsequent tolerance of the pyroplasma proved satisfactory.

It is difficult to explain the moderate effect of the considerable mass of blood injected in such cases, as compared with the deadly effect of the small amount that could come from the insertion of the rostra of even 50 or 100 ticks. But perhaps the venomous saliva instilled in concentrated form into the bites, protects the pyroplasma in the very limited area, until it gains sufficiently in numbers and force to hold its own even in the circulating blood.

Limited Value of Artificially Induced Tolerance. It must be added that all these measures for securing a partial immunity in the individual animal, and which enable us to safely introduce previously susceptible cattle into an infected district, virtually imply the continuance of the infection and infection bearer (boöphilus) for all time. They give no promise of the extinction of the bovine infection at even a remote future time, nor the abolition of the taxes for prevention, which must oppress the southern cattle owner so long as the disease continues. They are most valuable measures truly, but mere temporizing ones at the best, and they could just as well give place to the more sanitary, economical and statesmanlike measures for its radical extinction.

Marketing of the Beef. The piroplasma is not communicable to man, so that the carcasses of well conditioned cattle, which bear the infection need not be rejected as human food. It is only in severe and advanced cases in which anæmia, emaciation and pallid innutritious muscles are marked features, that the flesh is objectionable, and then only as being somewhat lacking in nutriment and digestibility,—not because of poisonous qualities. Danger of infection to cattle might be apprehended, but, if used outside the infected area, the second condition of the disease—the boöphilus—is lacking, while within the existing area of prevalence of the fever, the propagation from the carcass to the animal is infinitely less likely than from one live animal to its fellow.

Federal Restrictions on Cattle within Infected Areas. The orders of the Secretary of Agriculture prohibit the removal of cattle from the following states and territory into any states that extend northward of the line indicated: California, Oklahoma, Indian Territory, Arkansas, Tennessee, Virginia and the states south of these to the Gulf of Mexico. Exceptions are made in the case of fat cattle, sent out of an infected area, for immediate slaughter at the point of destination; conveyed in cars or boats placarded as containing Southern cattle and receiving no other; fed and watered enroute in yards that admit no local or other cattle and which can be reached without passing over any highway or unfenced open ground; and unshipped at their destination directly into yards reserved for Southern cattle only and within the same enclosure as the slaughter house. If reshipped the cars used must be subjected to the same restrictions. The cars, boats, chutes, alleyways, pens and troughs are to be disinfected by thorough cleaning; by saturation of all wood work, etc., with a mixture of 1½ ℔s. lime, ¼ ℔. phenic acid and 1 gallon of water, or ¼ ℔. chloride of lime in a gallon of water, or a jet of steam under a pressure of 30 ℔s. to the square inch. The manure and litter must be mixed with quicklime, or saturated with a 5 per cent. solution of carbolic acid, or secluded in a well fenced enclosure from February 1st to November 15th of each year. This is made the duty of the stock yard companies.

Cattle may be freely moved north from the infected area at any time from November 1st to December 31st, if inspected by an officer of the U. S. Dept. of Agriculture and found free from infection.

Provision is also made for sending infected cattle northward at any season, if they have been first dipped and pronounced free from the disease by an inspector of the department.

Cattle from Mexico are admitted under analogous rules.

PROTOZOAN ICTERO HÆMATURIA IN SHEEP. PALUDISM OF SHEEP. CARCEAG.

This is described by Babes and Starcovici as prevailing among sheep in the delta of the Danube, and held by them to be identical with the Roumanian Hæmoglobinuria of cattle (compt. rend. de l’Acad. des Sciences, 1892). Its essential cause is a piroplasma affecting the red blood globules, and very analogous to that of the protozoön of Texas fever, but its especial election for the sheep shows a specific difference, inasmuch as the Texas cattle fever does not attack sheep. Not only the parasite, but the symptoms and lesions as well, furnish a close counterpart to those of the cattle infection. It remains to be seen whether the pathogenic difference is due to a distinction in the piroplasma or to the absence from the Southern States of America of the particular tick or other insect which attacks the Danubian sheep.

Bonome (1895, Virchow’s Archives) describes the same disease as prevailing in Italy, describing the parasite and lesions at great length.

Finally my colleague Dr. W. L. Williams, and later Dr. Knowles, have identified the disease in the upper part of Deer Lodge Valley and the lower part of Silver Bow Valley in Montana, prevailing among sheep only, extending year by year, and proving disastrous to the sheep husbandry. Sheep were introduced into these valleys as early as 1875, but it was only in 1891 that the flock masters recognized the existence of this disease. By 1895 it prevailed over an area of 300 square miles. It made its advent in 1891 in four or five large flocks (2,000 to 10,000 head each) on land which they had occupied for nine years, and so disastrously that several sheep ranchers, after an experience of a year or two, sold out to the butcher and abandoned the sheep industry.

All or nearly all cases seen in 1896 were in parturient ewes, (4 to 6 days after parturition), the constitutional condition attending on lambing proving a most potent factor in causation.

The protozoön repeated the characters of that found in the sick sheep in Italy and the Danubian delta, and the conditions of the blood and the structural lesions supported the idea of identity.

Altitude seems to have little or no effect as a causative factor, as the disease is domiciled alike on the low alluvium of the Danube and the Deer Lodge Valley of Montana over 5,000 feet above the ocean. In both regions there is the common condition of inundation or its equivalent irrigation, for the Montana range is dry and arid, interspersed with alkaline bogs inimical to vegetation, but prolific and fruitful under irrigation. The Montana disease has been attributed to mineral poisons carried on the winds from the extensive copper smelters in Butte and Anaconda, but the smelters had been in existence for eight or ten years before this disease was observed, and from its appearance the infection has gradually extended, attacking sheep only, and sparing other domestic animals, which would have suffered as well from a mere mineral poison on the vegetation. The doctrine of a mineral poison is equally contradicted by the habitual prevalence of the disease in spring and autumn, while it is dormant in winter and summer. In winter the flocks eat hay cut from the richer valley lands and meadows, while in summer they are pastured on the foothills and mountains, and drink from the mountain springs surrounded by alkaline bogs. The autumn outbreak occurs long after the mountain grasses have dried up, when the flocks are thrown back on the supplies obtained from the alkaline bogs and the valley pastures. In late winter and early spring the growth naturally starts first in the same boggy and valley areas, and both facts suggest a microbian infection—protozoan or bacteridian. If an intermediate host or bearer—insect or other invertebrate—is to be assumed it implies two generations of these, a spring and an autumn one, in the same season, or otherwise a restriction of such invertebrate to the low valley pastures and the alkaline bogs on the higher levels, and that they disappear from the drier, arid areas in summer. It cannot be an obligate parasite like a louse or melophagus which would be constantly present, nor a musquito absent in early spring. But up to the present no invertebrate host or intermediate bearer has been identified. Cases were at first reported in the Angora goat, but this animal is now known to be immune.

Microbiology. The parasite is formed in the red globules and blood serum of the affected sheep and closely resembles the microbe of Texas fever. In the blood globules the parasite is seen in different forms, round, oval, oblong or curved and from one tenth to one sixth the diameter of the red globule. A single red globule may show from one to four of the microörganisms. They may at times show indications of division, and at others, automatic amœboid movements, from one portion of the blood globule to another, or from the periphery toward the centre. The affected blood globules are usually enlarged, having lost their biconcave outline, and become biconvex or spherical, with irregular crenated surface, and a dull, lustreless appearance instead of a clear red or yellow aspect. The protozoön stains readily in anilin red or methylene blue.

Lesions. The condition of the carcass was good or even high, in sheep attacked when in good flesh, and in which the affection ran a rapid and fatal course. In sheep attacked while in low condition on the other hand, the case tended to be milder and more prolonged, and the body was emaciated and anæmic. Dropsical swellings were common on the ears and sides of the head and neck.

The skin, connective tissue, fat, and other normally white tissues were usually of a yellow color, varying from sulphur to lemon color. The muscles were pale and soft with a yellowish tinge.

The blood was pale, thin and watery, especially in protracted cases, formed a loose coagulum, or remained fluid with a grayish red color. There was marked leucocytosis (1:4 or 5).

The stomach and intestines were more or less icteric, and contained little ingesta.

The liver was congested, softened, shrunken in protracted cases, colored of a deep yellow especially in the interior, and with gorged biliary radicles so that the acini stood out very prominently. The gall bladder was usually well filled with a thick, flocculent bile, yellowish green, blackish green or chocolate color.

The spleen appeared shrunken, somewhat spherical, 2 to 3 ozs., firm, and with a dark, reddish brown pulp.

The kidneys were greatly enlarged, weighing 12 to 16 ozs., dark red or bluish black, friable, and on section exuding freely a bloody or chocolate-colored liquid. The capsule was easily detached. The bladder contained a bloody or chocolate-colored urine, but was sometimes empty.

The heart cavities were empty or contained small diffluent blood clots. Petechiæ were common on pericardium and endocardium.

Yellowish or yellowish green gelatinoid effusion was often present, not only on the head and neck, but also on the inner side of the thighs, and in one or other of the serous cavities.

Symptoms. The first indications noticed are dulness, listlessness, a dragging behind the flock, ceasing to graze, arched back, and stiff or unsteady movements. There is moderate fever, yellowness of the visible mucosæ and skin, and rosy, bloody, or reddish brown urine.

Puffy dropsical swellings are noticed, especially on the ears, sides of the face, on the neck or thighs, and the patient lies down most of the time.

The patient usually dies in a state of collapse which has lasted for several hours, yet in certain cases it is preceded by a convulsive agony.