72 



DISEASES OF THE DIGESTIVE APPARATUS. 



of food (in old horses, and in the young during the eruption of 

 teeth). -We must also mention the ingestion of food and drink in 

 too large quautities. Indigestion through overloading the stomach, 

 which is very often the starting-point of catarrh, is usually pro- 

 duced through the change from poor to abundant feeding, or when 

 easily digested food is replaced by more or less indigestible sub- 

 stances. Animals are also very much exposed to catarrhal phleg- 

 masia of the stomach or intestine when subjected to an abrupt 

 change from dry to green food, or the reverse; or if, when unaccus- 

 tomed, they partake of large quantities of watery grass fermenting 

 too easily — for instance, green clover. It can be produced, likewise, 

 in the horse by a prolonged abstinence, by heavy meals separated 

 by long intervals, by irregular eating, and may occur when the 

 horses get loose during the night and ransack the oat-box. 



The indirect causes of gastro-intestinal catarrh are : any violent 

 efforts, and work immediately after meals — the muscles attracting 

 the blood to the periphery and the digestive organs becoming 

 anemic; sudden changes of temperature — for instance, cold, mo- 

 mentarily congesting the digestive mucous membrane, and thus 

 producing the first stage of catarrh ; great heats, very low atmos- 

 spheric pressure, etc., may also cause the trouble. Besides these 

 causes, catarrh may also be produced through a weakened consti- 

 tution, or colds resulting from badly built, unclean, and damp 

 stables with defective ventilation. In some countries gastro-intes- 

 tinal catarrh assumes an epizootic form at certain periods. Infectious 

 catarrh is caused by the introduction of certain micro-organisms 

 into the intestine ; notwithstanding its specific cause, it is here often 

 difficult to distinguish it from common acute catarrh or plain gastro- 

 enteritis. Finally, we observe sometimes a symptomatic, secondary, 

 gastro-intestinal catarrh accompanying various febrile diseases — for 

 instance, pneumonia, canine distemper, puerperal fever, petechial 

 fever, etc. 



Patholog'ical anatomy. We rarely have occasion to make an 

 autopsy upon animals that have died from essential gastro-intestinal 

 catarrh ; it is, indeed, exceptional to see it produce death. When, 

 however, it coexists with another affection which carries off the sick 

 animal, we can observe minutely any alterations it has produced in 

 the stomach and intestine. 



1. Alterations of the stomach. The pyloric portion of 

 the mucous membrane is tumefied ; sometimes it is uniformly red, 



