SUBACUTE OBSTRUCTION OF THE DOUBLE COLON 83 



distribution of his intestines, together with their com- 

 paratively fragile structure and the enormous loads they 

 are called upon to carry, and the natural bars to vomition. 

 His judgment should also be guided by a due considera- 

 tion of such physiological reasons as the short length of 

 time the food requires to remain in the digestive tract, 

 the matter of age and defective teeth, hereditary predis- 

 position, and the question of temperament. I would also 

 enjoin on him not to forget the effects of change of 

 climate, all those little errors resultant on the horse's 

 domestication : the matter of correct feeding and proper 

 watering, the length of his hours of work and rest, and 

 the number of times he is fed in the day. Among all 

 these will be found numberless causes of obstructive 

 colic. More particularly still would I request him to 

 bear in mind such causes as the collection of sandy or 

 gravelly deposits in the colon from the ingestion of fodder • 

 so contaminated, the weakening and lowering of tone of 

 the intestinal muscles consequent on debilitating diseases, 

 aneurismal interference with the blood-supply to various 

 portions of the digestive tube, and the presence of the 

 foetus in animals heavy with foal. 



Of these and others fuller details will be found in the 

 chapters mentioned. All are likely, in their turn, to have 

 a preponderating influence in determining an attack of 

 ' intestinal obstruction.' Nevertheless, we may correctly 

 sum up by declaring that a very great majority of the 

 causes of intestinal impaction are directly referable to 

 errors in diet. 



Symptoms. — These will be found to vary, in greater 

 or less degree, in nearly every case the veterinary surgeon 

 is called upon to attend. Before proceeding, however, it 

 will be wise to remind the reader that I am not dealing 

 with acute intestinal obstruction (under which head 



6—2 



