48 CLINICAL VETERINARY :MEDICINE AND SURGERY. 



after the lapse of a few days. In either case post-mortem examination 

 showed rupture of the diaphragm, usually in the tendinous portion ; a 

 recent extensive rupture with bleeding margins, through which the 

 abdominal viscera had entered the chest. Contraction of the abdo- 

 minal muscles had thrust the viscera violently against the diaphragm, 

 overcoming its resistance. Overloading of the intestines, and of the 

 stomach in particular, favours rupture. Chronic hernise, consequent 

 on extensive ruptures in the central portion of the diaphragm, are 

 produced by the same mechanism, but in this variety the primary 

 symptoms gradually diminish, and the lesions, though never repaired, 

 do not necessarily prove fatal. 



Injuries to the costal region opposite the insertion of the diaphragm, 

 and fracture of the last ribs, are also fairly frequent causes of diaphrag- 

 matic hernia. In these cases the opening is often of small dimensions, 

 and in the peripheral (muscular) portion of the septum. In fracture 

 of one or several ribs, resulting from a fall, or from the violent impact 

 of a comparatively soft body, the skin may not be penetrated, or may 

 only be excoriated, while the extremities of the bones, being violently 

 thrust back, rupture the muscular zone of the diaphragm at some 

 point, producing a rent through which one of the abdominal organs 

 may enter the thorax. As a rule, hernia soon follows the rupture. It 

 may, however, be postponed to a later period, when the borders of the 

 wound have to some extent cicatrised, — the rent, however, remaining 

 patent. Passage of abdominal organs into the thorax through one of 

 the normal openings in the diaphragm is somewhat rare — it could 

 scarcely occur except after dilatation of the oesophageal foramen. 

 Congenital hernia need only be mentioned — it is still rarer than the 

 preceding. In this case the opening in the diaphragm results from 

 arrest in development. 



In these various forms of diaphragmatic hernia, intestine and 

 epiploon are the structures oftenest found in the thorax. A narrow 

 slit is sufficient to allow of their passage. Displacement of the 

 stomach and spleen, of the small colon, of a part of the liver, or of one 

 of the flexures of the large colon, is less common, and only occur 

 when the opening is of very large dimensions, as in our case, in which 

 the stomach, spleen, the greater part of the epiploon, a long loop of 

 small intestine, and a loop of the small colon had entered the chest. 

 However small the diaphragmatic rent, several organs may pass through 

 it. The position they assume varies : for instance, a loop of small 

 intestine and a portion of epiploon may become lodged between the 

 two pulmonary lobes ; considerable masses of the same organs, or of 



