Part 65

Tubercles of the Skin. These are not very uncommon in cattle being the counterpart of the tuberculous warts and ulcers of the hands of butchers, tanners and others that handle the products of diseased animals. They may show as little pea-like nodules in the substance of the skin, or immediately beneath, very commonly on the side of the abdomen, where their presence in life furnishes a useful suggestion, as enlarged masses forming raw, warty projections with centres of caseation, or as clusters of warty-like growths of this kind (grapes).

Tuberculosis of the Muscles. This is comparatively rare in cattle, though by no means unknown, appearing as tubercles of the size of a pea and upward, in or between the muscular masses, often showing a caseated centre.

Tubercle of Lymph Glands. No organs in the body suffer more than the lymph glands as they receive through their afferent trunks and develop the bacilli coming from any adjacent tissue to which they are subsidiary. There is also evidence to show that bacilli entering from the lungs or bowels may pass through these without apparent effect to develop in the connected lymph glands. The frequent infection of the pharyngeal, bronchial, mediastinal and mesenteric lymph glands has been already sufficiently noticed, and if the other groups suffer less it is mainly because the tissues from which they derive their lymph are less frequently infected. An intimate knowledge of the different groups of lymph glands is a most essential prerequisite to the diagnosis of tuberculosis in life, and no less to a satisfactory post mortem examination. The order of relative susceptibility and importance is somewhat as follows: Bronchial, mediastinal, mesenteric, hepatic, sublumbar, mammary inguinal, subdorsal, phrenic, intercostal (especially the first and second), pharyngeal, parotid, submaxillary, prescapular, prefemoral (stifle), prepectoral, axillary, cubital and popliteal.

Relative Frequency of Tubercle in Different Parts in Cattle. The following table gives the seat of tubercle as noted by a number of observers. It is open to the objection that it is the result of examination for diagnosis, and therefore gives the most obvious rather than the complete list of lesions. Examination of the brain, bones, deep muscles and intermuscular glands, etc., was usually omitted. Again, as the animals were often steers, the indications as regards the generative organs are unreliable. The œsophagostoma nodules on the bowels have been so often mistaken for tubercles that I have omitted all reference to intestinal tubercle.

DISTRIBUTION OF TUBERCLES IN DIFFERENT ORGANS OF CATTLE: PER CENT OF AFFECTED CATTLE.

────────────┬─────┬───────────┬────────┬──────────┬──────┬─────── │ % │ │ │ │ │ │Right│ % │% Costal│ │ │ │Lung.│Mediastinal│Pleura. │ │ │ │ % │ Glands. │ % │ % │ │ │Left │% Bronchial│Visceral│Mesenteric│ % │ % │Lung.│ Glands. │Pleura. │ Glands. │Liver.│Spleen. ────────────┼─────┼───────────┼────────┼──────────┼──────┼─────── German │ │ │ │ │ │ Abattoirs,│ 75 │ 29 │ 47–55 │ │ 28 │ 19 Pearson, │ │ │ │ │ │ (Penna), │63–57│ 60.7–33.8 │ 22 │ 23.25 │ 20.7 │ 5.7 Bryce │ │ │ │ │ │ (Canada), │77.27│ 56.8 │ 11.36 │ 11.36 │ 40.9 │ Reynolds │ │ │ │ │ │ (Minn. │ │ │ │ │ │ Agr. Ex. │ │ │ │ │ │ Station), │89.4 │ 33.3–64.9 │ 79 │ 12.5 │ 35.4 │ 27 Law (N.Y. │ │ │ │ │ │ Grade │ │ │ │ │ │ Herds), │34.8 │ 64 │ 6.4 │ 9.6 │ 1.6 │ Nelson (N. │ │ │ │ │ │ J. Exp. │ │ │ │ │ │ Station │ │ │ │ │ │ Cows), │33.9 │ │ │ │ 28 │ Russell │ │ │ │ │ │ (Wis. Exp.│ │ │ │ │ │ Station), │ 55 │ 72.4 │ │ 24 │ 10 │ Stalker & │ │ │ │ │ │ Niles (Ia.│ │ │ │ │ │ Exp. │ │ │ │ │ │ Sta.), │ 36 │ 61 │ │ │ 8.3 │ Reick │ │ │ │ │ │ (Leipsic),│ 100 │ │ 57 │ │ 83 │ 18 ────────────┴─────┴───────────┴────────┴──────────┴──────┴───────

────────────┬───────┬───────┬───────┬───────────┬──────────┬────────── │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ % │% Liver│ │ % │ │ % │Lumbar │ Lymph │ % │Pharyngeal│ % │Uterus.│Glands.│Glands.│Peritoneum.│ Glands. │Diaphragm. ────────────┼───────┼───────┼───────┼───────────┼──────────┼────────── German │ │ │ │ │ │ Abattoirs,│ 10 │ 5 │ 1 │ │ 4 │ 0.2 Pearson, │ │ │ │ │ │ (Penna), │ 5.5 │ │ 10.3 │ 14 │ 15.15 │ 11.4 Bryce │ │ │ │ │ │ (Canada), │ │ │ │ 45 │ │ 2.27 Reynolds │ │ │ │ │ │ (Minn. │ │ │ │ │ │ Agr. Ex. │ │ │ │ │ │ Station), │ │ │ 8.3 │ │ 18.7 │ Law (N.Y. │ │ │ │ │ │ Grade │ │ │ │ │ │ Herds), │ │ │ │ 17.7 │ 6.4 │ Nelson (N. │ │ │ │ │ │ J. Exp. │ │ │ │ │ │ Station │ │ │ │ │ │ Cows), │ │ │ │ │ │ Russell │ │ │ │ │ │ (Wis. Exp.│ │ │ │ │ │ Station), │ │ │ │ │ 31 │ Stalker & │ │ │ │ │ │ Niles (Ia.│ │ │ │ │ │ Exp. │ │ │ │ │ │ Sta.), │ │ │ │ │ 5 │ Reick │ │ │ │ │ │ (Leipsic),│ │ │ │ 57 │ │ ────────────┴───────┴───────┴───────┴───────────┴──────────┴──────────

────────────┬────────┬──────┬────────┬──────┬──────┬───────── │ │ │ │ │ │ │ │ │ │ % │ % │ │ │ │% Iliac │Lymph │Lymph │ │ │ │ and │Glands│Glands│ % Lymph │ % │ % │Inguinal│ of │ of │Glands of │Stomach.│Udder.│Glands. │Udder.│Flank.│Shoulder. ────────────┼────────┼──────┼────────┼──────┼──────┼───────── German │ │ │ │ │ │ Abattoirs,│ 0.16 │ 1 │ 0.06 │ │ │ Pearson, │ │ │ │ │ │ (Penna), │ 7.2 │ 8.75 │ │ 13.5 │ 9 │ 7.75 Bryce │ │ │ │ │ │ (Canada), │ │ │ │ │ │ Reynolds │ │ │ │ │ │ (Minn. │ │ │ │ │ │ Agr. Ex. │ │ │ │ │ │ Station), │ │ 16.6 │ │ │ │ Law (N.Y. │ │ │ │ │ │ Grade │ │ │ │ │ │ Herds), │ │ 6.4 │ │ │ │ Nelson (N. │ │ │ │ │ │ J. Exp. │ │ │ │ │ │ Station │ │ │ │ │ │ Cows), │ │ │ │ │ │ Russell │ │ │ │ │ │ (Wis. Exp.│ │ │ │ │ │ Station), │ │ 6.9 │ │ │ │ Stalker & │ │ │ │ │ │ Niles (Ia.│ │ │ │ │ │ Exp. │ │ │ │ │ │ Sta.), │ │ │ │ │ │ Reick │ │ │ │ │ │ (Leipsic),│ │ 17 │ │ │ │ ────────────┴────────┴──────┴────────┴──────┴──────┴─────────

────────────┬────────────┬──────┬────────┬──────┬────────┬─────── │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ % │ % │ % │ % │ % │ % │Pericardium.│Heart.│Kidneys.│Bones.│Muscles.│Larynx. ────────────┼────────────┼──────┼────────┼──────┼────────┼─────── German │ │ │ │ │ │ Abattoirs,│ 0.9 │ │ 0.7 │ │ 0.1 │ 0.13 Pearson, │ │ │ │ │ │ (Penna), │ 8.2 │ │ 2.1 │ 0.4 │ │ Bryce │ │ │ │ │ │ (Canada), │ │ │ │ │ │ Reynolds │ │ │ │ │ │ (Minn. │ │ │ │ │ │ Agr. Ex. │ │ │ │ │ │ Station), │ │ │ 2 │ │ │ Law (N.Y. │ │ │ │ │ │ Grade │ │ │ │ │ │ Herds), │ │ │ │ │ │ Nelson (N. │ │ │ │ │ │ J. Exp. │ │ │ │ │ │ Station │ │ │ │ │ │ Cows), │ │ │ │ │ │ Russell │ │ │ │ │ │ (Wis. Exp.│ │ │ │ │ │ Station), │ │ │ │ │ │ Stalker & │ │ │ │ │ │ Niles (Ia.│ │ │ │ │ │ Exp. │ │ │ │ │ │ Sta.), │ │ │ │ │ │ Reick │ │ │ │ │ │ (Leipsic),│ │ │ 52 │ 9 │ 49 │ ────────────┴────────────┴──────┴────────┴──────┴────────┴─────── Footnote 2:

All serosæ.

Swine. The lesions in swine, though essentially like those in cattle, differ in some particulars. The primary tubercles are more commonly pharyngeal or intestinal and mesenteric, in keeping with infection by ingestion; caseation will often proceed to liquefaction, so that the tubercles appear like grumous abscesses with irregular outlines and vascular growths on their walls; there is less tendency to cretefaction than in cattle; the muscular and intermuscular tissues and the lymph glands are far more frequently affected; ulceration of the pharyngeal and intestinal mucosæ is more common. The lungs, liver, spleen and visceral lymph glands are very subject to tubercle, the kidneys, uterus and testicles somewhat less so, and the nerve centres least of all. The serosæ are often involved and the seat of clusters of vascular or caseated neoplasms (grapes). The bones and joints also suffer, particularly in young growing animals.

Horse. The horse suffers much less frequently than cattle or swine, probably largely because of his outdoor life, his better tone as the result of muscular work, and the absence of the excessive milk secretion which is secured from cows and of the dangers from ingestion that attend on swine. Yet, according to Nocard, it is even more susceptible, and the disease once established is liable to advance more rapidly to a diffuse generalization. The lesions in the lungs and abdominal cavity resemble those of cattle, both in nature and abundance; tuberculous polypi and ulcers are more common; the visceral lymph glands (bronchial and mesenteric) are early and severely attacked; the liver and spleen suffer extensively, the serosæ somewhat less so; lesions have been noted in the vertebræ, skin and muscles (Cadiot). In rare instances tubercles have been seen in the heart, and the aorta has been atheromatous (Cadiot). Necrotic degeneration, caseation and cretefaction occur as in cattle.

Sheep and Goat. Tuberculosis is infrequent in the goat and especially so in the sheep, owing perhaps largely to open air life and their predilection for high, airy pastures. When inoculated they show a marked susceptibility, and under favorable conditions they contract the infection casually. The tubercles may be found in all parts of the body,—lungs, thoracic lymph glands, intestines, mesenteric and sublumbar glands liver, spleen, serosæ, lymph glands at large, vertebræ, etc. There is less tendency to calcification than in the ox, the older tubercles remaining in the caseated condition or bursting and forming vomicæ. A common seat of casual tubercle in sheep is around the throat or on the sides of the cranium or face.

More frequently than in cattle, verminous affections (œsophagostoma columbiana, and venulosum in the bowels, stongylus filaria and rufescens in the lungs, linguatula denticula in the mesenteric glands) are mistaken for tuberculosis, hence the necessity for a careful investigation into the nature of the neoplasm, the presence of the tubercle bacillus, and the absence of the worms and their eggs. Except in the case of the linguatula the lymph glands are little affected by the worms.

Dog and Cat. The lesions are often concentrated on the respiratory or alimentary tract, but they have been noted also in the pharyngeal glands, tonsils, posterior nares, serosæ, liver, pancreas, spleen, nerve centres, ovary, uterus, testicle, epididymus, tunica vaginalis, prostate, heart, aorta, bones and joints. They follow the regular development of bovine tubercle, and caseation and cretefaction are prominent features. These animals are especially liable to infection by eating the left victuals from the plate of a consumptive owner, as well as by devouring consumptive prey, and the primary lesions are to be looked for along the line of the throat, bowels, liver and lungs. For the dog Cadiot records caseating polypi and ulcers on the mucosa of the larynx, trachea and bronchia, and Müller and Cadiot several cases of pharyngeal caseating adenitis in the dog bursting externally and developing intractable fistulæ, having abundance of bacilli in the discharge. These he attributes to expectorated virus from old standing tubercles in the chest infecting the pharyngeal mucosa and indirectly the lymph glands. The infection entering with the food and lodging in the follicles of the tonsils would act in the same way, and infected wounds received in fighting must also be quoted. Cats suffer from similar intractable sores, some of which may be traced to a tuberculous origin. The lungs are often extensively hepatized and of a general pale grayish color, but the early miliary lesions, the caseating and cutaneous centres, the vomicæ often intercommunicating, the tuberculous bronchial and mediastinal glands and the bacilli show the true nature. Intestinal ulcers are common, especially on the agminated glands, and small tubercles, in all stages of degeneration are met with in the enlarged liver, the spleen, pancreas, kidney, etc.

Apes and Menagerie Animals. In these tuberculosis is common alike in the thoracic and abdominal forms, and the lesions in the main are those of domestic cattle.

Chickens. The lesions are common in the abdominal cavity, the intestines, liver and spleen being the most frequently attacked, while the subcutaneous connective tissue, bones and joints also suffer. The lungs and kidneys usually escape. The intestinal mucosa shows small nodules, often caseated, or ulcers; the enlarged and friable liver is studded with tubercles from the size of a hemp seed upward, gray or translucid, homogeneous or with central necrosis, simply or in conglomerate masses, with congested or hæmorrhagic periphery; the spleen is swollen and permeated by similar deposits; fibrinous ascitis is not uncommon; the abdominal lymph glands are enlarged and congested.

The early tubercle shows a central, necrotic, hyaline area, consisting of the debris of disintegrated cells, which is colored brown by picro carmine, unlike the nucleus of the pheasant tubercle (Cadiot). Around the hyaline centre is a zone of large epithelioid cells, the nuclei of which stain strongly in carmine. Outside this is the usual zone of small, round, lymphoid cells. In the whole the tubercle bacilli can be made manifest by the carbol-fuchsin (Ziehl-Neelsen) stain. In the older and larger tubercles the central necrotic mass has encroached in part or in whole on the epithelio-lymphoid zone.

Pheasant. The lesions have the same seats and naked-eye aspect as the chicken tubercle, but under the microscope the smallest and most recent tubercles show epithelioid cells to the centre, or later, the central zone presents a dense fibrous network enclosing open spaces and giving a mahogany stain with Lugol’s solution (iodine and potassium iodide). (Cadiot). There has been an organisation of connective tissue which has submitted to amyloid degeneration, making a clear distinction from the tubercle of chicken.

Parrot. The lesions were thus located by Eberlein and Cadiot:

│ Cadiot.│Eberlein. Eye and periocular region, │ 12│ 14 Commissure of the beak, │ 7│ 11 Tongue, │ 8│ 9 Palate, │ 4│ — Larynx, │ —│ 2 ──────────────────────────────┼──────────────────────────────┼───────── Bones and Articulations, │Upper limbs (wings), 7│ 14 „ │Claws, 3│ — „ │Cervical, Dorsal and 5│ — │ Caudal, │ ──────────────────────────────┼──────────────────────────────┼───────── Lungs, │ │ 7 Liver, │ │ 4 Intestine, │ │ 3 Muscles, │ │ 1 Heart, │ │ 1

The skin lesions are vascular neoplasms containing bacilli and usually invested with a covering of horn, but sometimes, on the legs and feet raw. The morbid growth may be rounded or conical, narrowing to a point. The lesions of the buccal mucosa begin as small, grayish swellings on the angle of the mouth, palate, tongue or larynx which grow out into more or less rounded vegetations. The lesions of the liver and lungs are mostly miliary with the usual tubercular features, but they may grow to larger size, as a pea or bean. In the cancelli of bones and on their surface, the lesions resemble those of the mammal.

The cutaneous form has been held to be the counterpart of warty lupus of man, the more plausibly that the disease is developed by inoculation from tuberculous men. The arthritic type represents what is described as gout in parrots.

In any case the recent miliary lesion presents the true tubercular type of a central giant cell or cells with bacilli, surrounded by epithelioid cells, and they in turn by small, rounded lymphoid globules.

PRIMARY AND SECONDARY INFECTION.

The estimate of the relative, early or late infection of two organs or tissues may often be made with reasonable accuracy from the fact that the lesions in one organ are old, caseated, calcified or sclerosed, while those in the other organ are all recent, with vascular environment and almost devoid of caseation or other degenerative process. We cannot safely predicate our decision on the greater number of old lesions in one organ rather than another, as the disease may have advanced much more rapidly in the one tissue. Still less can we state with certainty that the disease has not entered by a given channel because no lesions are left to show the transit of the bacillus along its supposed course. We frequently find tuberculosis of the bronchial or mesenteric glands, when we can detect no lesion in the lung, nor intestine. The bacillus has been passed on without establishing any lasting lesion in transit.

It is often too confidently asserted that the infected dust inhaled, falls directly on the air cells and determines the extensive pulmonary tuberculosis that ensues. So, on the other hand, it is often too arrogantly assumed that tubercle bacilli ingested with food, must necessarily show their results mainly in the intestines, mesenteric glands and liver. That solid particles can find their way directly into the lungs, has long been demonstrated by the pulmonary anthracosis of the miner, and the deadly phthisis of the stone hewer and cutler. The experiments of Cornet, Tappeiner and others in producing pulmonary tuberculosis, by compelling the inhalation of infected spray, corroborate this experience very satisfactorily. Yet it does not follow that all of the offensive matter penetrated the air cells at once on the air inhaled. The heavy particles of steel, quartz and even of coal dust must be mainly arrested on the surface of the moist air passages, yet, under the irritation caused by their presence and the consequent arrest of the ciliary motion, they would slowly gravitate downward to the pulmonary cells. In the case of the inspired tubercular spray or dust, we must recognize the possibility of the approach of the bacillus to the lungs through the lymph and blood channels as well. The bacilli lodged in the pharynx, and, above all, in the tonsillar follicles, can readily enter the lymph vessels, and are finally poured into the lower end of the jugular vein, but a few inches from the right heart, by which they are instantly propelled into the lungs. If then the lung is the most receptive and least resistant organ, it may easily be that this is the first point where the bacillus can establish a strong and effective colony. Apart from this the colonization of the tonsillar follicles may determine a constant supply of fresh bacilli, which may gravitate down with the abundant mucus toward the lungs.

This tuberculous colonization of the tonsillar follicles is doubtless the main source of the infection of the pharyngeal lymph glands, which is so common in ox, pig and dog. It tends further to intestinal tuberculosis through the frequent swallowing of the products of the infected follicles. Then the infection of the pharynx and tonsils, whether established by inhalation or deglutition, may be the first step toward a secondary infection of the intestines.