152 Veterinary Medicine. 



both horse and ox, any lack of ptyaline being counterbalanced 

 by the presence of amylopsin in the intestines. 



Such paresis and indigestion, however, are more common as 

 the result of a general debility or a special gastric atony caused by 

 disease, starvation, overwork or fatigue. In all acute febrile and 

 inflammatory diseases the gastric functions are weak or sus- 

 pended, and if the animal is tempted to eat, the ingesta is un- 

 affected by the digestive fluids and forms a suitable fluid for 

 injurious fermentations. In convalescence especially, when the 

 starved system once more craves support, tempting food is 

 liable to be taken to excess, unless the attendant is especially 

 judicious and careful in grading the feed as the .stomach can dis- 

 pose of it. The horse that has been .starved must be fed little and 

 often, of easily digested material until the gastric functions are 

 restored. Long continued severe work, exhausts the motor and 

 secretory power of the stomach, as it debilitates the sy.stem at 

 large, and the animal may be at first unable to digest a feed of 

 grain even if he will take it. In such a case as in that of the 

 very hungry glutton a drink of gruel or a handful of hay which 

 he must masticate will often obviate the danger. 



Violent exertion immediately after a meal arrests digestion, 

 and tends to a fatal indigestion. An animal fed grain and im- 

 mediately put to severe work, or subjected to confinement for a 

 painful operation, may die in two hours from tympanitic indige.s- 

 tion. 



This weakness of the digestion may come from profuse bleed- 

 ing, from the anaemia caused by parasites (sclerostomata), or 

 from injuries to the pneumogastric nerves or their centres. It 

 can be produced experimentally by cutting both vagi ; the gastric 

 contents then remain packed and .solid, without peptic juices and 

 without digestion. 



Iced water, like frozen food, may temporarily arrest the gastric 

 functions and entail fermentation. It acts mo.st dangerously on 

 the overheated and exhausted horse, and though the indigestion 

 may not prove fatal, it may induce a .sympathetic .skin eruption 

 or laminitis. The mere exposure to external cold is less to be 

 dreaded as there is a compensating stimulus which drives the 

 blood to internal organs, the stomach included. Standing in 

 cold water or wading or swimming a cold river, is commonly less 

 injurious than a full drink of iced water, when heated and fatigued. 



