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 mass; 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. Fröhner 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, penis, anus, testicle, vulva, 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.