Chapter 36

The methods described above apply only to the animal in a normal condition. Before operating everything should be examined to see that it is as it should be. If otherwise, a special operative procedure will be necessary. Whichever mode of operation is adopted from a practical standpoint, the principal precautions to be taken in order to attain success are as follows: First, thorough cleanliness under strict aseptic and antiseptic precautions; second, a free and boldly made incision; third, the avoidance of undue pulling or tension upon the spermatic cord; fourth, free drainage, which can be maintained, provided the original incision has been properly made.

The operation of castration of the male is by no means a serious one, and when properly performed there is little danger from complications. Although the danger is trifling, the complications which may arise are sometimes of a serious nature. Hemorrhage, either primary or secondary, tetanus (or lockjaw), abscesses, hernia (or rupture), gangrene, and peritonitis are the most serious complications that follow castration. Whichever complication arises will require its own special treatment, which we will not go into here, as it will be fully dealt with under another heading. We would add, however, that, generally speaking, the animal, after being castrated, should either be regularly exercised or be allowed freedom so that it can exercise itself. Sudden changes of the temperature are dangerous. The animal should be fed moderately, but of a diet easily digestible.

CASTRATION OF THE FEMALE.

The operation of ovariotomy (spaying) should be performed when the heifer is in her prime and in moderate condition not too plethoric and not in heat or pregnant. This operation may be performed in one of two ways--namely, by the flank or by the vagina--each operation having its special advantages. In the flank operation the animal may be operated upon either while standing or while in the recumbent position. If standing, she should be placed against a wall or a partition and her head held by a strong assistant. The legs also must be secured to prevent the animal from kicking. A vertical incision should be made in the left flank, about the middle of the upper portion, care being taken not to make the opening too far down, in order to avoid the division of the circumflex artery which traverses that region. The operator should now make an opening through the peritoneum, which is best done with the fingers. Next the hand and arm should be introduced into the abdominal cavity and the hand directed backward toward the pelvis, searching for the horns of the uterus; if followed up the ovaries will easily be found. They should then be drawn outward and may be removed either by the Ècraseur or by torsion. Closing and suturing the wound will complete the operation. An adhesive plaster bandage can be beneficially applied.

The operation by the vagina is more complicated and requires special and expensive instruments. The mode of procedure in brief is as follows: A speculum is introduced into the vagina, and an incision is made into the superior wall of that passage about 2 inches from the neck of the uterus, cutting from below upward and from before backward. An incision which should not exceed 3-1/2 inches in length should be made. The next step is to get possession of the ovaries. They are situated in a fold of the broad ligament and should be drawn carefully through the incision into the vagina. Now take the long-handled scissors, specially made for this purpose, with which the thick border of the broad ligament is divided. The torsion forceps are introduced and applied to the broad ligament above the ovary. The left hand is then introduced, and the thumb and the index finger grasp hold of the broad ligament above the forceps. With the right hand torsion is applied and the ovary removed. The other ovary may be removed in the same manner.

What has been said with regard to complications and aftertreatment in the case of the male also applies to the female.

OTHER SURGICAL OPERATIONS.

Descriptions of other surgical operations not given in this chapter may be found in other parts of this work by reference to the index.

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SURGICAL OPERATIONS.

DESCRIPTION OF PLATES.

Plate XXVI. Devices for casting cattle. (From Fleming.)

Fig. 1. Reuff's method of throwing or casting the ox.

Fig. 2. Miles's method of throwing or casting the ox.

Plate XXVII. Surgical instruments and sutures. (After Reynders and Fleming.)

Figs. 1 and 2. Seton needles. These may be either long or short, straight or curved, according to the locality in which a seton is to be inserted.

Fig. 3. Various forms of surgical needles.

Fig. 4. Suture forceps or needle holder, for passing needles through thick and dense tissues.

Fig. 5. Knot properly tied.

Figs. 6, 7, 8, 9, 10. Various forms of sutures. Fig. 6, interrupted suture; 7, quilled suture; 8, uninterrupted suture; 9, twisted suture, made by passing suture pins through the parts to be held together and winding the thread about them so as to represent the figure 8; 10, single-pin suture.

Fig. 11. Appliance for ringing the bull, one-fourth natural size.

Fig. 12. Nose clamp, with spring and keeper.

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TUMORS AFFECTING CATTLE.

By JOHN R. MOHLER, V. M. D.,

_Chief, Bureau of Animal Industry._

[_Synonyms:_ New growth, neoplasm, neoformation, pseudoplasm, swelling, and hyperplasia.]

_Definition._--Tumors[3] are abnormal masses of tissue, noninflammatory and independent in character, arising, without obvious cause, from cells of preexistent tissue, possessing no physiologic function, and characteristically unrestrained in growth and structure.

Tumors are abnormal masses of tissue. The application of the term "tumor" is directly connected with the fact that they produce local enlargement.

They are noninflammatory; that is, the process of inflammation is not directly the cause or accompaniment of them. An inflammatory new growth tends to disappear upon the subsidence of the inflammatory process, while spontaneous disappearance of a tumor is comparatively rare.

Tumors are independent. For instance, their nutrition bears no relation to the nutrition of the body. A lipoma, or fatty tumor, in the subcutaneous tissue, may go on increasing to huge bulk while the body is steadily emaciating. Again, the tissues of the aged gradually undergo atrophy, yet cancers arise at this time and grow rapidly.

Tumors are unrestrained in growth and structure. In the development of an animal we know at what period of its existence the mass of tissue called liver will develop--what its site, structure, and size will be. We know that it will remain only in that locality, and not, as it were, colonize throughout the system. With tumors it is different; there are no laws by which we can forecast the time, place, nature, or size of development of them. There is no cartilage in the kidney or parotid gland, yet a chondroma, or cartilage tumor, may develop in either. Even when a new growth of tissue is started by an injury and consequent inflammation--as, for instance, proud flesh--there is a limitation of its size, but the controlling influences which govern the size of an organ or normal mass of tissue and limit the extent of an inflammatory overgrowth are all absent in the case of tumors. They are unrestrained, lawless.

Metastasis expresses the lawlessness of tumors as regards being limited to the original site of development. Small particles of tumors enter the blood vessels or lymph streams and are carried to distant parts of the body, where they lodge and start new tumor formations. Expansion by colonization in this manner is a rule with many tumors, and, since they exercise no function of use to the organism, this dissemination of actively growing particles becomes a menace to the system by numerically increasing the body's burden, opening new channels of drain upon the system and adding new centers for the absorption of putrefactive materials when the secondary tumors shall have degenerated. It is this which makes metastasis such an important element in the malignancy of tumors.

Tumors possess no physiological function. They are absolutely useless. Fibrous tumors bind no parts of the organism together; bony tumors add nothing to the supporting framework of the body; the tissue of fatty tumors never serves as a storehouse of feed and energy; the cells of an adenoma, or gland tumor, furnish no secretion; a tumor composed of muscle tissue produces no increase to the strength of the individual--its muscle cells are not contractile.

Tumors arise from cells of preexistent tissue. Tumor tissue is not a new variety. Whatever the structure of a tumor, its counterpart is found among the tissues of the body, the lawlessness of the tumor, however, showing itself in more or less departure from the normal type. This departure is usually a reversion to a more elementary or embryonic stage, so that the tumor tissues may be said to be structurally immature.

Tumors arise without obvious cause. Concerning the ultimate cause of tumor formation we are absolutely ignorant. Various theories have been advanced from time to time, but none of them have been applicable to more than a limited number of cases. The most important theories may be briefly mentioned.

(1) _The theory of tumor diathesis._--Bilroth taught that tumors are caused by a peculiar predisposition consisting of a diseased state of the fluids of the body. This constitutional taint might be acquired, but, having been acquired, is also hereditary. This theory is known also as the heredity hypothesis, but, while it is true that heredity appears to play some role in the causation of certain neoplasms, its application is too limited to make it of value.

(2) _The mechanical or irritant theory._--Virchow assumed that tumors arise as the result of previous irritation of the part. This has been noticed particularly in the case of certain cancers. They frequently develop on the edges of old ulcers, thus being dependent apparently on chronic irritation. Cancer of the lip in pipe smokers is a case in point. Cancerous tumors of the skin often develop on the arms of workers in paraffin, tar, or soot, the chemical irritation of these substances being the cause. On the contrary, the proportion of those thus affected among the exposed is very small and forces the conclusion that if the real cause were in the irritation vastly more cases would occur.

(3) _The theory of nervous influence._--That is based upon (_a_) the observed fact that tumors occur more frequently in man and the higher animals than in those lower in the scale, among which the nervous system is less highly developed; (_b_) that certain formations seem to be directly connected with nerve distribution, while others have been associated with alternations in neighboring nerve trunks.

(4) _The embryonal theory._--This is known also as Cohnheim's hypothesis. In early fetal life there occurs a production of cells in excess of those required for the construction of the various parts of the body, so that a certain number of them are left over in the fully developed tissue or become misplaced during the sorting of cells for future development of tissues and organs. These cells lie dormant until favorable conditions arise or until some sufficient stimulus is applied, when, released from their inactivity, they begin to reproduce and grow. Not being normally related to their site, they lack the controlling and limiting influences of the part, and, their embryonic character enduing them with a most potent proliferating power, they develop in a lawless and unrestrained manner. There are tumors whose existence can be explained only on these grounds. Still, this theory falls far short of answering the question as to the origin of tumors.

(5) _The parasitic theory._--This is not only one of the latest, but, merely as a hypothesis, it is the most attractive and plausible of all. The serious objections to it, however, are the almost uniform failure that has met the attempts to transplant these tumors from one animal to another and the absence of any constant variety of organism in them. Several forms of parasites have been found in certain tumors, but nothing definite has been shown with reference to the relation they bear to the causation of the neoplasm.

CLASSIFICATION OF TUMORS.

In Senn's work on tumors occurs the following: "A uniform system of classification of tumors is one of the great wants of modern pathology, and all attempts in this direction have proved failures." It would be folly, therefore, to burden the pages of a work of this kind with one or several of the proposed systems which have, admittedly, at some important point, failed of their purpose. Since the value of this chapter depends chiefly upon its practical character, which in turn is measured by its aid in diagnosis, prognosis, and treatment, the old but important clinical division is here adopted.

Tumors are either malignant or benign. The essential difference between the two classes is that while _benign tumors depend for their ill effects entirely upon their situation, malignant neoplasms wherever located inevitably destroy life._ The clinical features of each group are in many cases sufficiently marked to distinguish them.

MALIGNANT TUMORS.

(1) These are invariably pernicious, and from the beginning tend to destroy life.

(2) The cellular element predominates; therefore they grow rapidly.

(3) Possessing no capsule, they infiltrate surrounding tissues.

(4) They infect adjacent lymph glands.

(5) They recur even after complete removal.

(6) They give metastasis; that is, they become disseminated in different organs.

(7) Their presence develops a progressive emaciation.

BENIGN TUMORS.

(1) These in and of themselves do not tend to produce death.

(2) As the cellular element is not liable to predominate, they grow slowly.

(3) They are encapsulated, and when diffuse do not infiltrate surrounding tissues.

(4) They do not infect adjacent lymph glands.

(5) They do not recur after complete removal.

(6) They do not manifest metastasis.

Benign tumors, though harmless, may, by the accident of their location, indirectly produce death. Mere pressure on the brain substance of an otherwise innocent tumor, compression of the blood supply for vital organs, growth in such manner as to cause obstruction in the alimentary tract or pressure upon nerves, may cause death, or, prior to death, so combine the effects of anemia (deficiency of blood), starvation, and pain, with its consequent restlessness, as to produce a veritable cachexia (condition of general ill health).

On the other hand, a malignant tumor in its primary growth may so implicate a vital organ as to destroy life before metastasis can occur or even before cachexia can develop. Thus, to the untrained observer, environment may so operate as to cause these two classes of new growths to simulate each other. The boundary lines may seem to overlap. It is here that the microscope, as the court of last appeal, adjudicates positively in the diagnosis between these two clearly marked divisions.

It may almost be asserted that a true classification of tumors can not be made until we know more about the cause of them. The arrangement here presented is offered to meet the practical needs of the veterinarian, student, and farmer rather than of the pathologist.

We may roughly divide the tissues of the body into structural and lining tissues. The structural tissues are composed of the tissues of special function and simple connective tissues. The lining or covering tissues, both internal and external, are known as epithelium.

Section A of the table below contains the true tumors or proper neoplasms.

Section B includes the cysts, some of which are true tumors, while others are false ones, but the latter are added because of their gross resemblance to the true and the consequent necessity of considering them at the same time.

TUMORS AND CYSTS.

A.--Tumors.

BENIGN.

I.--_Tumors composed of tissues resembling those of special function._

1. Type of muscle tissue Myoma. 2. Type of nerve tissue Neuroma. 3. Type of vascular tissue Angioma. 4. Type of gland tissue Adenoma.

II.--_Tumors composed of fully developed connective tissue._

1. Type of fibrous tissue Fibroma. 2. Type of adipose, or fat, tissue Lipoma. 3. Type of cartilage tissue Chondroma. 4. Type of osseous, or bone, tissue Osteoma. 5. Type of neuroglia, or nerve, sheath Glioma. 6. Type of mucoid, or mucous, tissue Myxoma.

MALIGNANT.

III.--_Tumors composed of embryonic or immature connective tissues._

1. Type of immature connective tissue Sarcoma. 2. Type of endothelial tissue Endothelioma.

IV.--_Tumors in which epithelial elements predominate._

1. Type of various epithelial cells and associated tissues Carcinoma.

B.--CYSTS.

I.--_Cysts which develop in preexisting cavities._

1 Retention cysts. 2 Proliferation cysts.

II.--_Cysts which are of congenital origin and are true tumors._

1 Dermoid cysts.

III.--_Cysts which originate independently as the result of pathological changes and are nontumorous._

1. Cysts formed by the softening and disintegration of lesions Softening cysts. 2. Cysts formed around parasites Parasitic cysts. 3. Cysts formed by an outpouring of blood and lymph into the tissue spaces with subsequent encapsulation of the fluid Extravasation cysts.

TERMINOLOGY.--The principle of naming tumors is quite simple. The Greek word "oma" (plural "omata") means tumor. This word "oma" is added to the stem of the word ordinarily used to designate the kind of tissue of which the tumor is composed. Thus a tumor formed after the type of fibrous tissue is a fibroma. The only exception to this is in the naming of the two large classes of malignant neoplasms. There the names were formed from the fleshlike appearance of the one and the crablike proliferations of the other--namely, Sarcoma (sarks=flesh), carcinoma (karkinos=crab).

DIAGNOSIS.--In the diagnosis of tumors note is taken of (1) clinical history and (2) examination of the tumor.

(1) _Clinical history._--Circumstances connected with the origin of the tumor and its rapidity of growth may point to an inflammatory swelling rather than a tumor. The location of the tumor at its commencement is important, as, for instance, in diagnosing between lipoma and carcinoma, the former being more or less movable under the skin, while a carcinoma develops in the skin. While tenderness on pressure may be caused by compression of a sensitive nerve by a tumor or by tumors of the nerve or nerve sheaths, as a rule this symptom is indicative of inflammatory swelling rather than of the existence of a tumor.

(2) _Direct examination of the tumor._--In the application of this diagnosis the trained observer will note color, size, shape, and surface structure, transmission of light, movableness, consistence, resistance, pulsation, and crepitation. Percussion, auscultation, and exploration are also available methods. Finally, microscopic examination of the growing portions of the tumor by a pathologist will be found most satisfactory.

GENERAL TREATMENT OF TUMORS.

For benign tumors treatment is required only when it damages the animal's value or when merely for sake of appearance. When it is possible, the removal of the tumor by an operation is indicated. If the tumor has a small, constricted base, remove by torsion, ligation, or with an Ècraseur. Ligation following the incision of the skin with a knife avoids the pain of pressing on the sensitive nerves of the skin and is suitable for tumors of broad base and small bodies. A firing iron, such as is used in line or feather firing, may also be used in removing tumors with small attachments. This not only stops the bleeding but forms a firm scab, under which healing may occur rapidly. Those tumors that can not be removed by the above methods may be treated with caustics or acids, such as sulphuric acid, hydrochloric acid, caustic potash, arsenic, silver nitrate, or chromic acid, but it is difficult to limit the action of these drugs. The injection, into the tumor, of such chemicals as anilin dyes, alcohol, acetic acid, citric acid, or ergotin, is of doubtful value, as is also the injection of the germs of erysipelas--thought by some to be a specific. Certain specific tumors, such as actinomycosis and botryomycosis, may be successfully treated by the internal administration of potassium iodid, together with the injection into the tumor or the painting of its surface with either Lugol's solution or the tincture of iodin. The most reliable means of treating tumors is by extirpation with cutting instruments. Dissect the tumor from the surrounding tissue, ligating all the larger blood vessels, and tearing the tissues with the fingers rather than cutting with a knife. The bleeding may be stopped with a hot iron. The after treatment is the same as for any ordinary wound of similar size.

DESCRIPTION OF INDIVIDUAL TUMORS.

Although a full list of the tumors that may be found in bovines has been given above, there are a number that warrant a detailed description, and the following mention will be made of the most important of them:

MYOMA.

These tumors are after the type of muscle. They are sharply circumscribed and, as a rule, are very hard, a condition owing usually to combination with fibroma and are then known as fibromyoma. In fact, the clinical differentiation between myoma and fibroma is almost impossible. Myomas are found in the uterus, vagina, stomach, intestines, gullet, and bladder of a bovine animal. They grow very large, but, as a rule, are benign. Treatment should consist of their removal.

NEUROFIBROMA.

A true neuroma built up of nerve fibers and nerve cells is infrequent, if it ever occurs, in cattle. False neuromas, or neurofibromas, are knotty, spreading tumors of the size of a large potato, which are developed within the nerve sheaths and composed of nerve fibers and connective tissue bands interlaced. The commingling of these varied fibers is often so intricate that separation is practically impossible. This tumor is most frequently found upon the shoulder of cattle. Treatment is surgical.

ANGIOMA.

The angiomas are tumors composed mainly of blood vessels or blood spaces and are observed on the skin of man, where they are called "birthmarks" or "mother marks." Cavernous angiomas are seen in cattle, affecting the liver and the mucous membrane of the nasal septum. In the liver they appear as smooth, flat, nonprojecting tumors of a dark-red or purple color and of about the size of a silver 10-cent piece. They are somewhat softer in consistency than the adjoining liver substance into which they are gradually fused. These tumors are frequently observed by meat inspectors in livers of slaughtered cattle. Treatment of angioma is unnecessary.

ADENOMA.