Special Report on Diseases of Cattle Part 41

MYXOMA.

Characteristic myxomas are mucoid tumors which chiefly originate from the mucous membrane and are especially to be found within the nasal pa.s.sages and uteri of cattle. They can reach a size of three fists, are smooth or velvetlike, or may be lobulated, broad at the base, and consist of a gla.s.sy-looking ma.s.s of connective tissue, which usually shows a distinctive yellowish color. Being h.o.m.ogeneous and elastic, the moist, jellylike tissue composing the tumor may be easily destroyed or crushed. When cut through, these tumors soon collapse from the loss of their fluids. They sometimes inclose elliptical cavities filled with slimy, gelatinous ma.s.ses.

_Treatment._--Extirpation.

SARCOMA.

This is a malignant tumor after the type of embryonal tissue, and consists of several varieties, such as the round cell, spindle cell, giant cell, alveolar, and melanosarcoma. They grow by preference in connective tissue and are quite vascular. Sarcomas appear either as single or multiple nodules, varying in size from a hempseed to a hazelnut, or else as a moderate number of tumors of the size of hen eggs. Their surface, at first smooth, later becomes lumpy and tuberous from internal degeneration.

Secondary nodules may appear near the primary tumor. The outer skin is not involved so soon as in cancer, nor does ulceration follow so rapidly.

Sarcoma is about the most frequent and dangerous tumor that is found in cattle. It occurs in young animals, and is found on the serous membranes, in the glandular organs, and on the outer skin, especially of the neck and shoulders--in fact, in nearly every tissue and in almost every part of the body. This tumor is often found in places exposed to traumatisms and at seats of scars, or of irritations from pressure and inflammation.

_Treatment._--Treatment should consist in early and complete removal by the knife, including one-half or three-quarters of an inch of the sound tissue adjoining the tumor. If there is a possibility that sarcomatous tissue still remains, either cauterize the wound with a hot iron or powder the walls of the cavity with a.r.s.enious acid.

CANCER (CARCINOMA).

Cancers are tumors of epithelial tissues and are malignant. There are several varieties of cancers, such as hard, soft, and colloid, but only those growing on the surface will be mentioned here. These malignant tumors of the superficial organs develop primarily from the epidermis or from the glands of the skin. They appear secondarily as spreading infections from milk glands, thyroids, a.n.a.l glands, or as embolisms. In such cases their sole character depends wholly upon the kind of cancer from which they have sprung. The infiltrating cancer begins as an elevation of the skin, which progresses until it becomes rough and nodular. The surface later becomes attacked, and an ulcer results whose edges are outlined by a hard, firm zone.

The ulcerations may remain limited by cicatricial tissue, but it is more likely that the infiltration and destruction of tissue will spread out wider and deeper until a rodent ulcer (so called) is formed. One of the most frequent sites of cancer in cattle is in the eye, where they are called fungus hematodes, but they also occur on the skin, on the genitals, in the stomach, and within the organs.

_Fungus hematodes._--This starts at the inner corner of the eye as a papillary elevation or as small nodules which become fused. They grow larger and become papillomatous, with superficial ulcerations and a tendency toward hemorrhage. In some cases the eye is displaced by the growing tumor or is attacked by the cancer cells and entirely destroyed.

Cancerous growths upon the external genitals and the a.n.u.s usually present a rough, irregular surface from which there is a constant sloughing of decomposed tissue accompanied with a penetrating disagreeable odor.

The diagnosis of cancer may be made clinically by noting the simultaneous infection of the lymph glands which surround the primary lesion. Deeply burrowing and infiltrating forms which appear as lumps and ulcerations cause marked disfiguration of the affected part. The surface becomes a soft, greasy ma.s.s; later it cracks open and from the fissures blood-colored pus exudes, being continually formed by the moist degeneration of the tissues beneath. At first the general health of the animal does not appear affected, but later the cancer nodules spread to important organs and give rise to marasmus and progressive emaciation. Cancer is not a frequent tumor of cows. Frohner states that of 75 cases of tumors in cattle which came under his observation 2, or 2.6 per cent, were found to be cancers, while 20, or 26.6 per cent, were sarcomas.

_Treatment._--Treatment consists in the early and complete removal of the tumor, taking care to include a wide border of healthy tissue. This has been most successful in such superficial cancers as those of the eye, p.e.n.i.s, a.n.u.s, t.e.s.t.i.c.l.e, v.u.l.v.a, and sheath. If the disease has advanced too far, this treatment may not prove efficacious, owing to the great malignancy of the cancer and its tendency to recur. In such cases the animal may be slaughtered, but the flesh should be used for food only after inspection by a competent veterinarian.

CYSTS.

Cysts may be true or false tumors and consist of a capsule containing a fluid or semisolid content. Among the most important cysts, which have been briefly referred to in a previous table, the following are probably the most noteworthy, owing to the frequency with which they are found in bovines:

SOFTENING CYSTS.

Softening cysts, which result from the degenerative liquefaction of normal or diseased tissues, especially of tumors of different kinds, followed by the encapsulation of the fluid.

PARASITIC CYSTS.

Parasitic or foreign-body cysts, from the inflammatory reaction induced by such parasites as the echinococcus (hydatid cyst) or by the presence of various kinds of foreign bodies.

EXTRAVASATION CYSTS.

Extravasation cysts, caused by injuries which rupture blood vessels, followed by an increase of fibrous tissue which forms a capsule about the fluid. The hygromata in front of the knee in cattle, so-called tumor of the knee, and serous cysts belong to this variety.

HYGROMATA, OR TUMORS OF THE KNEE.--These consist in the simplest form of a collection of serous fluid mixed with fibrin within a distended bursa. The walls surrounding the fluid become firm, smooth, and dense.

Outwardly the tumor appears fluctuating, though tense, while the skin which covers it may be normal, denuded of hair, or covered with hard epidermal scales, possibly half an inch in thickness, forming a hard, h.o.r.n.y plate.

The cavity which contains the fluid may have the dimensions of a hen's egg, an apple, or a child's head. Its walls are formed by the diseased secreting membrane of the bursal sac, and are readily detachable from the subcutis of the skin. Their internal surfaces are often uneven or supplied with projections or tufted growths which support a fibrous network within the tumor.

Tumors of the knee may also a.s.sume a granular type, as the result of chronic inflammation or following operative or spontaneous evacuation of pus from the part. They are either firmly connected with the skin or are detachable from it, and when laid open disclose a whitish-red, porklike tissue surrounding a central nucleus of pus, or a fistulous tract leading to the outer surface. They are caused by the chronic inflammation which follows the bruises received by cattle in lying down and in rising, or they may be due to falls on uneven, hard ground.

_Treatment for hygromata._--When the swelling first appears cold water should be applied, followed later by bandaging with cloths wrung out of warm water. If the swelling is soft, it should be punctured at the lowest point, and afterwards the cavity should be syringed with Lugol's solution.

If the tumor is hard and nonfluctuating, a mercurial blister may cause absorption and at the same time prevent further injury to the part by making it more painful, thus sparing it.

SEROUS CYSTS.--These swellings are another variety of extravasation cysts, and are caused by such injuries as b.u.t.ting, running against hard objects, and shipping bruises, which are followed by an outpouring of blood and lymph into the tissue s.p.a.ces. These cysts develop rapidly and may reach the size of a man's head or even larger. They are soft, edematous, and hot at first and contain a serous or blood-tinged fluid. Later, partially organized clots and shreds of a fibrinous nature and of a gelatinous consistence are formed within, and the temperature of the swelling is reduced. They appear on the surface of the body, especially on the belly and flank of cattle.

_Treatment of serous cysts._--Treatment consists in opening the cyst at the most dependent point with a sharp knife. The cavity should be washed out twice daily with a 5 per cent solution of carbolic acid, and drainage encouraged by keeping the incision open.

DERMOID CYSTS.

These cysts have a wall which is almost an exact duplicate of the structure of the skin, and frequently contain epidermal structures, such as hair and teeth, which, in the development of the embryo, have been misplaced. Thus we may find in an ovary or t.e.s.t.i.c.l.e a dermoid cyst, containing a tooth or a ball of hair. Dental cysts are included in the cla.s.s above.

DENTAL CYSTS.--It happens occasionally that the teeth of cattle, instead of developing normally within strong supporting alveolae, remain inclosed within a cystic membrane, which a.s.sumes a tumorlike character. One tooth may be included alone in the cyst or a number may be inclosed together.

However this may be, the malformation progresses, especially if confined to the incisor teeth, until the remaining teeth that began to develop normally are crowded out of position and rendered useless. The tumor may reach the size of a man's fist. It appears to be fleshy and dents upon pressure, but it may also appear on closer examination as though it contained irregular sections of thin bone. The outer surface is always smooth, and no indication of purulence, softening, or scab formation is ever exhibited.

Upon being laid open with the knife the tumor is seen to be surrounded by a firm, smooth membrane which limits it completely from the adjoining tissues. It is filled with material which possesses partly edematous, partly fleshy, and partly bony properties. It is supposed that this ma.s.s is composed of rudiments of the jawbone or of the alveolar walls which, becoming spongy, lose themselves in the soft, fleshy ma.s.s contained within the capsule of the tumor. It occasionally happens that the tumor is hollow and that the cavity extends back into the body of the lower jaw for a considerable distance.

Tumors of this kind, being of congenital origin, are very naturally observed most frequently in young cattle, but they may continue to expand for a period of several months after the birth of the calf, even until they become troublesome and unsightly.

_Treatment for dental cysts._--Treatment consists in the complete extirpation of the cyst and the destruction of the lining pouch by curetting.

RETENTION CYSTS.

Retention cysts arise from the retention of normal secretions, owing to obstruction of a duct leading from a gland. The mucous cysts found in the mouth, udder, and vestibule of cows are samples of this form.

MUCOUS CYSTS.--Saclike dependent tumors, caused by retention of the secretions from the mucous glands, sometimes develop in the mouth, nose, pharynx, and v.u.l.v.a of cattle. They are called "mucous cysts." These are of sizes varying from peas to pigeon eggs, are roundish and translucent, and surrounded by a delicate, vascular membrane. They contain a siruplike substance more or less thick and transparent and whitish yellow in color.

Treatment consists in the puncturing of the swelling, if accessible, and the destruction of the cyst walls by the injection of Lugol's solution.

PROLIFERATION CYSTS.

These are found especially in the ovaries of cows, called "cystic ovaries,"

and may produce nymphomania (chronic bulling).

The treatment indicated in this case is the removal of the diseased ovaries.

FOOTNOTES:

[3] The term "tumor" literally means a swelling, and thus has been applied to the prominence caused by an overdistended bladder, to the enlargement of pregnancy, to the swelling produced by an abscess, to the overgrowth of tissue (hyperplasia) a.s.sociated with injury and consequent inflammation, and to numerous other phases of tissue enlargement directly connected with recognized disease processes. For this reason it is becoming more common for scientists to apply the word "neoplasm" to the new growths described in this chapter. Because of the still popular use of the word "tumor," it is retained in this chapter for the designation of those new growths to which the sevenfold characterization of our descriptive definition applies.