330 DISEASES OF CATTLE. 



tion, or obstruction to the flow of blood through the lungs. In debili- 

 tated animals and in some animals heavily infested with parasites 

 there is swelling of the dewlap or of the fold of skin between the jaws. 



Symptoms. — Painless swelling of a limb, udder, lower surface of 

 abdomen, or lower jaw becomes apparent. This may increase in di- 

 mensions for several days, or may attain its maximum in less than 

 twenty -four hours. Unless complicated with some acute disease of a 

 specific character, there is not much, if any, constitutional disturb- 

 ance. The deep layer of the skin is infiltrated with serum, which 

 gives it the characteristic condition of pitting under pressure. 



Treatment. — When the cause can be ascertained and removed, we 

 will have a reasonable expectation of seeing the edema disappear. 

 When no direct specific cause can be discovered and the animal is 

 debilitated, give general tonic. If, on the contrary, it is in good flesh, 

 give a purgative, followed by half an ounce of acetate of potash twice 

 a day. External applications are useless. 



Edema may be distinguished from erysipelas or anthrax by the 

 absence of pain and fever. 



DERMOID AND SEBACEOUS OTSTS (WENS). 



A dermoid cyst is formed by an involution of the skin, with a growth 

 of hair on the inner wall of the sac. It may become embedded deeply 

 in the tissues subcutaneously, or may just penetrate the thickness of 

 the skin, where it is movable and painless. They are generally found 

 within the ear or at its base, although they may form on any part of 

 the body. Usually they have a small opening, from which a thick, 

 cheesy matter can be squeezed out. The rational treatment is to dis- 

 sect them out. 



Sebaceous cysts appear not unlike the former. They are formed by 

 a dilatation of the hair follicle and sebaceous duct within the skin, 

 and contain a gray or yellowish sebaceous mass. The tumor may 

 attain the size of a cherry stone or a walnut. Generally they are 

 round, movable, and painless, soft or doughy in consistency, and 

 covered with skin and hair. They develop slowly. The best treat- 

 ment is to dissect out the sac with contents entire. 



VERRUCA (WARTS). 



Cattle are affected with two varieties of warts. One, the verruca 

 vulgaris, is composed of a cluster of enlarged papilla, covered with a 

 thickened epidermis, the number of papillae determining the breadth 

 and their length its height. They are generally circular in figure, 

 slightly roughened on the surface, and spring from the skin by a broad 

 base. Occasionally large numbers of very thin, long, pedunculated 

 warts grow from the skin of the ear, lips, about the eyes, and vulva. 

 Another variety, the verruca acuminata, sometimes erroneously 

 denominated epithelial cancers, are irregularly shaped elevations, 



