318 DISEASES OF CATTLE. 



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 f^nd 

 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 bod3% especiall}^ on the bellj'^ 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. 



DERMOro 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 testicle a dermoid 

 cyst, containing a tooth or a ball of hair. Dental cysts are included 

 in the class above. 



Dental cysts. — It happens occasionally that the teeth of cattle, in- 

 stead of developing normally within strong supporting alveolae, re- 

 main inclosed within a cystic membrane, which assumes 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 remain- 

 ing teeth that began to develop normally are crowded out of posi- 

 tion and rendered useless. The tumor ma}^ reach the size of a man's 

 fist. It ajapears to be fleshy and dents upon i^ressure, but it may also 

 appear on closer examination as though it contained irregular sec- 

 tions of thin bone. The outer surface is always smooth, and no 

 indication of purulence, softening, or scab formation is ever ex- 

 hibited. 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 

 partl}'^ edematous, partly fleshy, and partly bony properties. It is 

 supposed that this mass is composed of rudiments of the jawbone or 

 of the alveolar walls which, becommg spongy, lose themselves in the 

 soft, fleshy mass contained within the capsule of the tumor. It oc- 

 casionally happens that the tumor is hollow and that tile cavity ex- 

 tends 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. 



