68 



DISEASES OF THE DIGESTIVE APPARATUS. 



subjects, or when coarse food was partaken of {dyspepsia torpida). 

 The qualitative alterations were represented by an excess or absence 

 of acids in the gastric juice (dyspepsia ah acido, dyspepsia acida). 

 These essential dyspepsias were opposed to symptomatic dyspepsias, 

 which accompany febrile diseases. 



Physiological considerations on acute gastro-intestinal 

 catarrh in the horse. No department of special pathology 

 requires to a greater degree an exact knowledge of the physiologi- 

 cal phenomena which take place in the gastro-intestinal apparatus. 

 It is of importance to bear in mind the following points : 



1. Mastication favors digestion by increasing the salivary secre- 

 tion and the surface of the alimentary particles upon which the 

 gastric juice may perform its action. Insufficiently masticated food 

 produces troubles of digestion. 



2. Small meals, at short intervals, are digested more rapidly and 

 more completely than heavy meals given at long intervals. These 

 latter frequently produce digestive troubles and gastric catarrh. 



3. In the horse, on account of the large quantity of saliva swal- 

 lowed during the meal, the reaction of the stomach is alkaline or 

 neutral as long; as the ino^estion of food lasts : it reaches its mini- 



DO / 



mum of acidity immediately after eating (0.8 per 1000) ; the pro- 

 portion of acids increases then gradually as high as 2 per 1000. 

 When this proportion is passed there is abnormal acidity. Acidity 

 of the gastric juice of carnivorous animals is physiologically greater 

 than that of the horse. In febrile diseases such as influenza, intense 

 gastric catarrh, etc., the contents of the stomach are of a neutral or 

 even alkaline reaction, which is due to insufficient acidification of 

 the gastric juice (Ellenberger and Hofmeister). 



4. The first acid in the digestion of the horse is lactic acid : the 

 digestive action of this agent upon starch is considerable ; its maxi- 

 mum effect corresponds with the second hour of digestion. Hydro- 

 chloric acid and pepsin transform albuminoid matters into peptones. 

 The maximum activity of albumin digestion takes place three or 

 four hours after absorption of the food, in ordinary meals; in 

 heavier meals, between the sixth and eighth hour. Therapeutic 

 administration of hydrochloric acid during the period of lactic 

 digestion is injurious, injection of large quantities of water during 

 the period of hydrochloric acid digestion is equally so on account 

 of the extreme dilution of this acid (Ellenberger and Hofmeister). 



5. Digestion of albumin can only take place when acid is present. 



