ABDOIMINAL WOUNDS OF ANIMALS 157 



]\Ianifestatioii of such injuries may be evident within 

 a few hours after they occur, or they may pass unno- 

 ticed until much subsurface extravasation or discharge 

 of fluids has taken place. In some cases, only a small 

 amount of blood escapes into the tissues, little swelling 

 occurs at first, and not until infection has taken place is 

 there marked inconvenience manifested by the subject. 

 Abscesses occurring in this manner often contain large 

 quantities of pus, and it is a noticeable fact that such, 

 conditions may persist for weeks at a time without per- 

 foration of the abdominal wall from necrosis. 



To differentiate between abscess of the abdominal wall 

 where there exists a large cavity filled with fluctuating 

 detritus, and hernia, is not easy in certain cases. In 

 vicious horses, where the condition is painful, little is 

 to be learned by palpation w^hile the subject is standing. 

 By casting such animals and placing them in such a posi- 

 tion that the swelling is located uppermost, one can ex- 

 clude hernia by absence of perforation of the underlying 

 structures, and failure at reduction of the mass. Finally, 

 by using an exploratory trocar or needle, hernia can be 

 excluded. 



Where such abscesses involve one or more floating ribs, 

 necrosis is likely to result in perforation of the abdom- 

 inal wall, and being situated nearer the superior part of 

 the abdomen, swelling is not so extensive and it is more 

 defined. 



Treatment of such cases consists in evacuation of all 

 pus and the removal of shreds of necrotic tissue. Such 

 abscesses should be so opened that perfect drainage may 

 take place and little after-care be necessary. 



An extreme case of this kind was treated by the writer 

 in 1906. The subject was a gelding weighing eleven hun- 

 dred pounds. He was very vicious, and the owner had 

 given him little or no attention. Not until the swelling 



