BRUISES OF THE ABDOMINAL WALLS. 509 



firm, inflammatory swellings result. When larger vessels are 

 ruptured, swellings (hsematomata) resembling hernise are produced. 

 In large animals extensive extravasations commonly develop in the 

 subcutis, or under the panniculus, but are rarely seen under the 

 slightly elastic, yellow abdominal tunic. The tunica abdominal is 

 may likewise be divided, and the rupture mistaken for a hernial 

 opening. But such faulty diagnosis is less serious than when a hernia 

 is mistaken for an extravasation or an abscess. 



Progress. Simple inflammatory swellings, even when of moderate 

 size and situated on the yellow abdominal tunic, are more easily 

 reabsorbed than large hsematomata. But when the swelling dis- 

 appears, a portion of the abdominal contents may present itself under 

 the skin. From its fluctuating character this new swelling may be 

 mistaken for an abscess. An abscess, however, is distinguished 

 by its periphery of firm tissue, and sensitive, softening centre. When 

 an abscess forms, it generally perforates outwardly, seldom discharges 

 into the peritoneal cavity and, when opened, usually heals. In- 

 flammatory processes invading the peritoneum cause thickening, and" 

 occasionally lead to adhesions limiting the movements of the bowel, 

 the walls of which may give way, as Curdt has noticed in the horse. 

 Haematomata undergo a course similar to that of inflammatory 

 swellings, but their resorption is less probable. On their breaking 

 or being opened, they discharge offensive fluids and sometimes gas. 



In cattle, less frequently in the other domestic animals, chronic 

 abscesses occur in the walls of the abdomen. The cause may escape 

 observation, the injury remaining unrecognised for a considerable 

 period, and like those of strangles, chronic abscesses may have a 

 metastatic origin. In cattle especially, months may elapse before 

 any change is noticed, but then the swelling suddenly and rapidly 

 increases, becomes painful, sometimes contains gas, may produce 

 high fever, and, if not opened, soon breaks. 



The appearance of the swelling, as before stated, may vary. It 

 may be firm, hard, and painful : sometimes it is fluctuating. When 

 recent, it is often associated with oedema, especially in deeper lying 

 neighbouring parts, under the belly. As pointed out, it may be 

 mistaken for a hernia, and the rule should be observed not to operate 

 before being perfectly convinced of the absence of rupture. The 

 compressibility of the hernia is certainly characteristic, but never- 

 theless mistakes easily occur. In doubtful cases, an exploratory 

 puncture may be made with antiseptic precautions. 



Treatment. Newly developed swellings are first treated with 

 cold applications to prevent further extravasation ; subsecpiently 



