10 MASTITIS OF THE COW 



WOUNDS OF THE UDDER 



Etiology. — Wounds of the udder may be produced by 

 blows, or stabs as by a pitch-fork, hooking, or from a sur- 

 gical operation such as an incision in an abscess. 



This brings us to the discrimination between the pri- 

 mary lesion and the subsequent inflammation. 



The wound ruptures the vessels and milk passages, fol- 

 lowing which the walls of the wound become infiltrated 

 with blood, lymph and milk which flow outward through 

 the mouth of the wound. The hemorrhage may be more 

 or less copious. It is greatest following incisions and least 

 in contused wounds, that is in wounds produced by dull 

 objects, as a thrust from a horn. In contused wounds the 

 vessels of the neighborhood are so injured that thrombosis 

 occurs in most of them. This prevents hemorrhage but 

 predisposes to necrosis. 



Inflammation. — The reactive inflammation begins in 

 the immediate vicinity of the wound, that is, the walls of 

 the wound, where a wall of emigrating cells [phagocytes] 

 is formed which clears the wound of dead tissue and foreign 

 particles. Around this a connective-tissue wall is formed 

 which closes the ruptured tubules and from which con- 

 nective-tissue cells rapidly proliferate until the wound aper- 

 ture is gradually fiilled with young succulent loose con- 

 nective tissue, granulation tissue. 



Termination. — In the most favorable cases the wound 

 heals without any complication. The newly formed connec- 

 tive tissue fills the wound aperture, and the surface is finally 

 covered by regeneration of the epidermis from the margin 

 of the wound. The exudate is resorbed and the loose con- 

 nective tissue strongly contracts, finally leaving a white 

 fibrous line or scar. 



As a rule, however, udder wounds become complicated 

 with infection. In these conditions healing is usually de- 

 layed, necrosis of the connective tissue is more widespread 



