TUMORS AFFECTING- CATTLE. 317 



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 seventy-five cases of tumors which came under 

 his observation in cattle two, or 2. 6 per cent, were found to be cancers, 

 while twenty, 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 contain- 

 ing 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, due to 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 dis- 

 tended 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, horny plate. The cavity which contains the fluid may have the 

 dimensions of li hen's egg, an apple, or a child's head. Its walls are 



