Milk Fistulcs 985 



a somewhat resistant wall is formed around the escaped blood. 

 The hematom may then be opened and the blood removed, after 

 which the lesion is to be handled as an ordinary wound. 



16. Milk Fistula. 



A milk fistula consists of a communication of the milk cistern or 

 one of the large milk canals with the exterior, through a canal 

 other than the normal one. While such fistulse are possible in 

 any animal, they occur, or are observed, practically in the cow 

 alone. Their very rare occurrence in other animals is of little or 

 no significance. The fistulse may be congenital, but generally 

 they are caused by penetrating wounds of the milk cistern during 

 the period of lactation. They arise from trauma of various 

 kinds, and in some instances result from operative wounds, or 

 from abscesses forming in the milk cistern or large milk sinuses 

 and rupturing outward through the wall of the teat or udder. 



Symptoms. Milk fistulse may open at any part of the teat, 

 or of the udder near the teat base. They are most common in 

 the teat near its base, though sometimes observed at the apex of 

 the teat, within a very short distance of the normal opening. If 

 the fistulous opening is very small, the milk may not flow from 

 it except when the teat is being milked and greater pressure is 

 consequently placed upon the fluid within the cistern. If the 

 fistulous opening is large, the milk drops away continually when- 

 ever the pressure of the milk in the cistern is sufficiently high. 



Fistulse of the milk canals tend to heal spontaneously in a com- 

 paratively short time, while those of the milk cistern, and espe- 

 cially those of large size, do not readily heal of themselves, and 

 are liable to become permanent unless active intervention occurs. 

 If the fistula forms somewhat early, during active lactation, its 

 walls tend to become healed and covered over by a protective 

 epithelium, so that they will not readily adhere. If the perfo- 

 rating wound occurs while the cow is dry, or if she ceases to milk 

 before the walls of the fistula become covered over with epithe- 

 lium, adhesion of the wound margins, with spontaneous oblitera- 

 tion of the fistula, is probable. 



Treatment. Perforating wounds of the milk cistern or canal 

 should be handled as soon as possible after their occurrence. The 

 handling should consist essentially of the thorough and careful 

 disinfection of the wound, after which it may be neatly sutured 



