448 OPEKATIONS ON THE DIGESTIVE APPARATUS. 



distokia. They may also form one of the complications of some 

 of the forms of the treatment of umbilical hernia. In the 

 smaller animals, such as dogs, they may be produced by a severe 

 bite by a larger animal. 



The pathognomonic symptom of an eventration may be con- 

 sidered the protrusion of a portion of the abdominal contents 

 through its lacerated walls. If the opening through which this 

 takes place is small, the viscera will appear as a small round tumor, 

 which presently becomes transformed into a large mass of intes- 

 tinal circumvolution, which itself varies in dimensions, according 

 to the extent of the laceration. As the exposed intestines begin 

 to protrude, they for a period retain their physiological appear- 

 ance and normal color, but they undergo rapid changes, becoming 

 progressively darker, blueish and then black, and grow cool to the 

 touch. The viscera as they protrude from the abdomen may be 

 quite intact, but they often are injured, bruised or torn, the con- 

 ditions varying according to the peculiar circumstances attending 

 the accident. And not only is this so, but the sequel of the case 

 must be especially considered, since an eventration which possible- 

 might be susceptible of cure, if carefully tended from the first, 

 may become so aggravated and exaggerated as to preclude aU 

 possibility of remedy, as when the wounded creature, frantic with 

 pain, from colics and otherwise, in rearing and struggling, forces 

 his entrails more and more out of their place, and tears and tram- 

 ples them upon the earth until they become a mere mass of crushed 

 and bruised viscera, ground into the earth. And yet, colics are 

 not always present in eventrations, even in horses whose irritable 

 temper, combined with the condition of the injured parts, would 

 naturally tend to render their occurrence quite inevitable. 



The prognosis of their injuries varies according to the species 

 of the animal, and also under the special condition and circum- 

 stances of each case, as judged by itself. In horses, it is, in the 

 majority of cases, a fatal accident. The sensitiveness of the animal 

 to impressions upon the nerves, and the delicate susceptibHity of 

 the peritoneum account for this. In ruminants they are less 

 serious, and certainly still less so in carnivorous animals, where 

 sometimes the whole intestinal mass may be seen hanging through 

 the laceration, and with extensive co-existing inflammation, with- 

 out the occuiTeuce of a fatal termination. 



Swine are also very sensitive to this kind of injury, though the 



