COLIC DUE TO INVAGINATION. 165 



Colic persists with great intensity for ten to twelve hours,. interrupted 

 only by rare periods of calm. At the end of this time, however, it may 

 suddenly disappear, and the animal may fall into a semi-comatose state. 

 This indicates the onset of necrosis in the invaginated section, the painful 

 reflexes no longer being transmitted to the sympathetic system. The 

 disappearance of colic is sometimes regarded as a sign of improvement, 

 but this improvement is illusory. From this time onwards the animals 

 stand stolidly, obstinately refusing both food and drink. If they lie down, 

 it is with great care. Palpation of the right side of the abdomen is 

 painful, and the animal actively resents it. One of the most important 

 and constant signs at this stage is the absence of defaecation, due to ob- 

 struction of the intestine, which is occluded. The animals may survive 

 for ten, twelve, or even fifteen days (see also Moller and Dollar's 

 "Regional Surgery," loc. cit.). The invaginated, necrosed portion may 

 even be passed with the fieces, and recovery may occur, the continuity of 

 the intestinal tube being secured by the adhesion of the serous surfaces ; 

 l)ut such spontaneous recoveries are exceptional. Usually after a few 

 days death results from peritonitis. 



Occasionally, trifling invaginations may become reduced spontaneously. 

 Diarrhoea, with the passage of blood-stained material is then seen for a 

 time, a sign which alone at this stage would justify the diagnosis of 

 invagination. 



Diagnosis. The intensity of the colic and the absence of defeca- 

 tion for several days afterwards, justifies the diagnosis of invagination. 

 Purgatives then remain without effect. In addition, rectal exploration 

 offers a valuable means of diagnosis. The last portions of the intestine 

 are found absolutely empty, and the arm when withdrawn is found to 

 be covered with viscous blood-stained mucus, resulting from the sero- 

 sanguinolent exudate, due to compression of the blood-vessels. 



In cases of this kind accompanied by the above-mentioned symptoms 

 abdominal exploration by the rectum should always be practised, but it 

 rarely gives exact information. The hand, when passed towards the 

 right flank, may sometimes reach the invaginated part, which conveys the 

 impression of a cylindrical swelling. The invagination, however, can 

 rarely be reached. If the operator is successful, he will find that as he 

 displaces this cylindrical mass or attempts to grasp it, the animal shows 

 signs of exaggerated sensitiveness. 



The prognosis is of exceptional gravity. Apart from the rare cases 

 where the invaginated portion becomes necrotic and is eliminated, death 

 is inevitable. Unless an operation is performed, septic peritonitis may 

 develop about the fifth or sixth day. 



Treatment. The only treatment consists in surgical intervention. 

 Some practitioners have recommended giving large doses of purgatives 



