Part 57

Hardened sections show an enormous development of the follicles at the expense of the medullary walls, and double nucleated white globules packed in a rich reticulum of adenoid tissue, whilst the bloodvessels in the connective tissue are crowded with white cells, and there are slight ruptures, old or recent.

=Lesions of the Spleen.= These are nearly always present. Leisering found a horse’s spleen over three feet long and 28 lbs. weight, and Nocard one of 13 lbs. Bollinger found a pig’s spleen 3½ lbs. Siedamgrotzky found dog’s spleens over 2 lbs. The consistency is usually firm (sometimes soft in dog). Capsule thickened and white, cut surface dry, reddish brown, granular, Malpighian bodies enlarged like a pea, hazel nut or walnut, with contents as in the lymph follicles. The capillaries are enlarged and crowded with white cells.

=Lesions in the Liver.= The liver is enlarged in one-half of the cases of leukæmia in the lower animals. It has been found to weigh 20 lbs. in the horse, and 4 lbs. in the dog. It is of a grayish brown, or yellowish brown hue, or light red spotted with yellow, or mapped out by anastomosing grayish white lines. There may be enlargement of the acini, or the formation of little nodes of adenoid tissue, or most commonly in the lower animals, there is an adenoid thickening of the bands of connective tissue extending in from the capsule. These are filled with white cells which stain deeply with carmine. There may also be slight extravasations of blood and infarcts.

Lesions in the Bone Marrow. These noticed in the pig by Fürstenberg, and in dogs by Siedamgrotzky, consist in increased vascularity, great cell hyperplasia, and formation of adenoid tissue as described under leukæmia.

=Lesions of the Intestine.= These commence in the agminated or solitary glands, which become enlarged, causing thickening of the mucous membrane, and later grow out into more or less rounded masses of lymph—adenoid tissue up to an inch in thickness. They are quite subject to ulcerations.

=Lesions of the Tonsils.= Bollinger, Nocard and Siedamgrotzky found these enlarged in dogs in connection with adenoma of the spleen. They were soft, friable, grayish, and consisted of a very delicate and fragile adenoid tissue.

In one case Siedamgrotzky found adenoid hypertrophy of the thymus in a cow, and adenoma of the kidneys similar to that of the liver has been noticed.

Similar adenoid hyperplasia has been found in the lungs, the bronchial mucous membrane, the pleura, the mediastinal and bronchial glands, and the pericardium. In man this has invaded the nerve centres, and it seems that at any point where there is a lymph gland or a lymph plexus this adenoid hyperplasia may localize itself.

Symptoms. The general symptoms of failing health are as described in leukæmia. The particular symptoms of this disease consist in the recognition of the adenoid hyperplasia in the absence of a marked leucocytosis. The submaxillary glands are usually the first attacked, and the disease may, in the horse, be confounded with glanders. There is, however, no pituitary discharge nor ulcer, the glands are enlarged symmetrically on the two sides, and a careful search will usually discover other groups with similar symmetrical enlargement. The parotidean, the pharyngeal, the prepectoral, the prescapular, the axillary, the popliteal, the prefemoral, the post and premammary, and the inguinal should be critically examined. The enlarged mesenteric glands may be reached and detected by the hand engaged in the rectum, or in the small animals by external palpation, as may also the enlarged spleen or liver.

The adenoid hyperplasia in the chest offers very obscure and uncertain symptoms. The enlarged bronchial and mediastinal glands may seriously interfere with the functions of the vagus nerve, causing, in cattle, disturbed digestion and rumination and tympanies, in horses stertorous breathing, and in the carnivora and omnivora a tendency to vomiting. In animals generally the pressure on the cardiac nerves leads to great irritability of the heart, and violent action under any exertion. The prominent dyspnœa in the advanced stages may be explained by these thoracic hyperplasiæ.

Nocard claims that the urine furnishes most important indications in its low specific gravity (horse 1010), its constant acidity, and in the almost entire absence in that of the horse of hippuric acid. When there is any suspicion of tuberculosis or glanders, the tuberculin or mallein test will decide.

Treatment is essentially the same as in leukæmia, and equally unsatisfactory. Arsenic has in the main given the best results. In the very earliest stages when the granular hyperplasia is confined to one group, excision is advisable. This should be avoided in all cases in which the constitutional symptoms have developed. Phosphorus and phosphide of zinc have seemed beneficial in certain hands. Injections into the glands have so far proved useless.

ACUTE LYMPHANGITIS OF PLETHORA IN HORSE. ANGEIOLEUCITIS.

Definition. Symptoms and causes. Genera affected. Causes of plethora. High feeding. Work followed by rest. Fever, hurried breathing, strong, rapid pulse, anorexia, stiffness and swelling in a hind limb, inguinal glands, connective tissue engorgement, corded lymphatics, suppuration rare. Mild forms. Lesions, in lymphatic vessels and glands. Chronic cases. Nature, plethoric, lymph excess, stasis, excess of cells and fibrine, immunity of the fore limb. Season of prevalence. Climate. Diagnosis, from farcy, erysipelas, etc. Treatment, exercise, friction, resolvents, purgative, bleeding, diuretics, astringents, iodine, pressure, diet. Prevention. Treatment of chronic cases.

Definition. Inflammation of the lymphatic vessels and glands of one limb usually in connection with rest.

Symptoms. This affection is common in heavy draft horses of a lymphatic temperament and kept on high feeding and at hard work. It rarely develops however while the subject is kept at steady work. But if, in the midst of such work, the horse is kept at rest in the stall over one, two, or more days on the same generous diet, he is found shivering violently, with rapid, labored, breathing, high pulse and elevated temperature, symptoms which have been frequently mistaken for those of pneumonia. There is complete anorexia, and often ardent thirst. The patient is indisposed to move and if forced to it shows lameness in one hind limb with an extraordinary abduction of the limb at each step, and sometimes so severe as to prevent his putting his full weight upon it. If an examination is now made high up in the groin close outside the inguinal ring, the lymphatic glands will be found to be swollen, hot and tender, so that under even moderate pressure the leg will be lifted and abducted until the patient threatens to fall on the other side.

A little later the shivering may have given way to the hot stage, with it may be general perspiration, and the swelling may have extended down the course of the saphena vein and lymphatics, as a distinct ridge and the lower part of the limb from the foot to the hock may be filled, dropsical and hot. Unless checked the swelling goes on increasing till the lower part of the limb is two or three times its natural thickness, and the swelling has extended well up on the thigh. The swelling has a soft œdematous feeling, easily receiving and retaining the imprint of the finger and is not only hot, but excessively tender. From the margin of the swelling, firm, tender, rounded cords are found to emerge passing upward along the line of the saphena vein and its branches toward the inguinal glands. These represent the swollen and gorged lymphatic trunks, and may often be traced for some distance into the substance of the general engorgement.

When the inflammation is violent, suppuration may ensue at one or several centers, but more commonly the engorgement goes on increasing and when the febrile attack has subsided the limb is left permanently enlarged and correspondingly liable to a second attack.

Milder cases are met with which are perhaps even more misleading. There may be little or no rise of temperature, loss of appetite or general constitutional disturbance, but under some change of regimen and particularly after one or two days of rest the subject becomes lame in one hind limb, without any of the usual injuries to account for it. Examination of the groin shows swelling and tenderness of the external inguinal glands, with or without, a tender cord-like swelling running down from them.

Between these two types may be found all grades of lymphatic inflammation with a varied degree of attendant constitutional disturbance.

Lesions. The coats of the inflamed lymphatic vessels are thickened by exudate and the outer coat is the seat of ramified redness with minute spots of blood extravasation. The inner coat is dull, opaque, or even thickened. The vessel is dilated and its walls friable. The contained lymph in the intervals between the valves has coagulated into a very thin diffluent jelly-like clot, which in old standing cases may have become granular. The connective tissue from which these vessels lead is infiltrated with liquid and the lacunar spaces distended. Red patches from blood extravasations are numerous. The external inguinal glands and often the internal and sublumbar are swollen, congested, and the seat of active cell hyperplasia. Abscesses are exceptionally seen.

In chronic cases the lymphatic vessels of the affected limb and especially of the lower part which is permanently swollen, are enormously increased in calibre (lymphangiectasis), and have their walls correspondingly thickened. The connective tissue is the seat of extensive fibrous hyperplasia, and its interstices are greatly enlarged.

Causes. Nature. This disease has not been sufficiently studied to ascertain what toxic agents are produced in the plethoric condition, under the torpid processes of nutrition and sanguification entailed by absolute compulsory rest. A consideration, however, of the relations of the lymph and lymph vessels and glands to other parts will in part explain the pathology of the malady. The lymphatics take their origin in the nuclear spaces of the various tissues, the anastomosing canals of such pericellular spaces together with the latter forming the actual radicles of this set of vessels. They receive, therefore, the surplus plasma which is not used up by the tissue cells in performing their trophic, secretory and other functions. This lymph carried on by the vis a tergo, muscular compression and other movements, is delayed in the adenoid tissue known as lymph nodes, and especially in the lymph glands, in which the proliferation of lymph cells is mainly carried on. Thus the lymph cells are very scarce in the lymph radicles of the connective and other tissues, and are found in greater numbers after passing through the lymph nodes, and in still greater after passing through the lymph glands. But the increase of cells is also in inverse ratio with the rapidity of the circulation of the lymph. When this is rapid the cells are hurried on and there is little time for their reproduction. When slow on the other hand, there is time for cell growth and division in the glandular detention cavities, and the ratio of cells to the plasma is materially increased. Consider next that the multiplicity of cells determines an increase of the fibrine factors, so that the more cells the lymph contains there is the more material for fibrine (Landois), and we have one good reason why under enforced rest the overcharged and congested gland may become the seat of fibrinous coagula or lymphatic embolism. Any overdistension, toxic element, or other cause of disturbance, which deranges the functions of the cell or causes its rapid multiplication by division—as in inflammation—at once sets free the fibrine ferment and determines the coagulation. In the disease before us we have the overfeeding of an animal having a strong digestion, we have an absolute compulsory inactivity, with a suspension to a large extent of the functions of nutrition, sanguification, secretion, and elimination; we have in consequence an increase of the blood pressure, and of the solids of the blood and of the plasma of the lymph; we have a suspension of the great motor force of lymph circulation, namely, the muscular contraction, and we have the consequent tardy movement of the lymph, the great increase of lymphocytes, and the distension and engorgement of the lymph glands. As soon as this has reached a certain stage the congestion and incipient inflammation of the gland determines the precipitation of fibrine, the obstruction of the gland, and of the entire circulation of lymph in the lower part of the limb. The fever, the local swelling, and the subsequent steps follow as a matter of course. This view is sustained by the fact that incipient cases can be cured by muscular movement alone. The rarity of the disease in the fore limb may be ascribed to the greater force of the vis a tergo, the lesser height of the lymph column, and the stronger action of the aspiratory power of the chest on the lymphatic vessels.

In addition to the causes mentioned above must be noted the following: The disease is an affection of heavy draft horses, in which the tissues are more lax, and the lymph plexus in the connective tissue of the hind limb is much more abundant. It is common in the heavy English, Scotch and Belgian draft horses, and rare in the English racer, the American trotter, and in the average light American horse. The malady is most frequent in spring and autumn, when the work is hardest and the feeding most abundant. It rarely attacks the horse in steady work, but appears after an idle Sunday spent in the stable (Monday morning disease), or after one or more days of compulsory idleness from heavy rains or other cause. The damp climate of western Europe has probably an exciting influence, as it has in producing the lymphatic constitution. In the same line of thought Zundel says that many cold weather attacks would be prevented by clipping off the heavy coat which keeps the entire system relaxed. In some cases a sudden change of food, and in others musty oats have been claimed as causes.

Diagnosis. Lymphangitis is distinguished from a simple dropsy of the limb by the acute fever, the great local tenderness especially of the inguinal glands, and by the tender corded lymphatics that enter these. From cutaneous glanders (farcy) it is diagnosed by the more acute fever, by the swelling of the inguinal glands in the early stage of the disease, followed by the swelling of the lower limb, and by the absence of the hard, comparatively insensible and prone to ulcerate, farcy bud. Farcy buds usually appear on the pastern or fetlock, with more or less swelling of the lower part of the limb, while the inguinal glands are as yet normal in size and without tenderness. From erysipelas, with which this has been confounded, it is distinguished, by the suddenness of the onset, under the circumstances above described, by the high type of fever, by absence of early cutaneous inflammation and the formation of vesicles, and by the fact that lymphangitis commences in swelling of the inguinal glands.

Treatment. In cases that are seen in the earliest stages, before the leg has become badly swollen, recovery will usually take place under active exertion continued for hours at a time. The pumping action inside the hoof during exercise, and the alternate compression and relaxation of the lymph vessels by the muscles, tend to establish a rapid current of lymph, to break up coagula and to re-establish a healthy condition. Friction from below upward on the lymphatic vessels and swollen limb will greatly assist in this restoration. Different agents are employed, such as camphorated spirits or oil, iodine, mercurial, and even blistering ointments. These should not replace exercise when this is possible.

When the fever has set in suddenly and runs very high, the abstraction of four or five quarts of blood, and the administration of a purgative (8 drs. aloes) will be in order. In cases occurring in the same stable and in all other respects apparently identical, the subjects of phlebotomy recovered without any permanent swelling of the limb, while those that were not bled recovered with thickened limb.

In cases so advanced that the limb cannot be used, cold irrigation, with friction, may be applied, and when the irrigation is intermitted one may apply some astringent (vinegar, alum, lead acetate), or an iodine lotion followed by an evenly applied bandage.