318 



DISEASES OF THE DIGESTIVE APPARATUS. 



times the peritoneum is covered with an exudate masking these 

 lesions. 



The serous membrane loses its transparence from the first ; it 

 becomes dull, takes a velvety appearance, and may easily be torn 

 or detached from the organs which it covers. Within a few days, 

 newly formed vessels are to be recognized, and it becomes filled 

 with an exudate that is very variable in character as well as in 

 abundance; according to the case, it may be covered with a thin 

 coagulated fibrinous layer forming a transparent membrane which 

 may be detached from the serous membrane by the slightest trac- 

 tion, where it forms a thick, clear or dark-yellow layer, similar to 

 the croupous membranes ; at times it forms adhesions between the 

 two folds of the peritoneum (mesentery) and the organs covered by 

 it (fibrinous or dry peritonitis). In serous or sero-fibrinous peri- 

 tonitis, the abdominal cavity contains a more or less considerable 

 quantity (as much as forty litres in the horse and the ox), of a 

 yellowish, reddish-yellow, or greenish-yellow liquid. This liquid 

 exudate is mainly formed of serum, fibrinous or purulent flakes, 

 and of cells undergoing destruction ; when it contains a large pro- 

 portion of red corpuscles, these latter will impart to it their colora- 

 tion. The red exudate is frequent in the horse (sero-fibrinous 

 peritonitis complicated with hemorrhage). If the peritonitis is due 

 to a perforation of the intestine consecutive to a disease of this organ, 

 the exudate, which is ichorous, has a very fetid odor (ichorous peri- 

 tonitis) ; ordinarily it is mixed with alimentary matters ; in peri- 

 tonitis caused by rupture of the bladder it exhales a strong urinous 

 odor. In the dog and cat it is often purulent (purulent peritonitis), 

 and forms a thin creamy covering upon the peritoneum, or again 

 becomes collected in the abdominal cavity in the shape of a turbid 

 flaky liquid with a fetid odor (mainly after the opening of the 

 abscess). 



When the peritonitis runs its course the exudates may be entirely 

 or partially reabsorbed, but their disappearance requires quite a 

 long time, as the cellular and fibrinous elements must first undergo 

 fatty degeneration and become disintegrated into small detritus. 

 After this reabsorption, some adhesions will frequently persist be- 

 tween the two folds of the peritoneum (adhesive peritonitis) ; new 

 connective tissue membranes and ligaments are formed which often 

 produce contractions, dilatations, or atrophy of the organs of the 

 abdominal cavity by undergoing cicatricial retraction. When the 



