488 DOGS USED FOR SPORT. 



the intestinal mucous membrane, but also chemically by means of 

 the putrefactive changes which take place in the retained faeces. 



Another very common cause of intestinal inflammation is the 

 influence of cold, which probably acts by driving the suddenly 

 cooled blood upon the surface of the body into the intestines 

 where the irritation excites increased peristaltis * and inflamma- 

 tion. Finally abdominal injuries may produce enteritis even of a 

 chronic character. 



In the second category of causes, are included all abnormal 

 conditions which induce a morbid hyperfemiat of the intestinal 

 mucous membrane. Chief among these are the passive conges- 

 tions in the portal circulation % produced by affections of the liver, 

 or of the portal vein itself, or by tumors compressing the mesen- 

 teric veins ; also the general congestions which occur in connection 

 with the diseases of the circulating system and of the air passages. 



According as the exciting cause of enteritis is of temporary, 

 frequently recurring, or permanent character, the affection runs an 

 acute or a chronic course. 



The disease is a very frequent one, and spares no age. Young 

 animals are particularly apt to be attacked, chiefly on account of 

 the sensitiveness of the intestinal mucous membrane in puppy- 

 hood, and the facility with which their food becomes decomposed. 

 Meteorological conditions are well known to influence the fre- 

 quency of the disease. The hottest months are regarded as having 

 especial influence, particularly when there is a rapid alteration of 

 day and night temperatures. 



The symptoms of this disorder are usually not very character- 

 istic, at least they vary considerably in their degrees of develop- 

 ment in different cases, and are very irregular in their occurrence. 

 Furthermore, the differences in the anatomical structure and the 

 functions of the various divisions of the intestine must modify the 

 symptoms to such a degree, according as the inflammation is differ- 

 ently situated, that it will be impossible to give a general descrip- 

 tion which is applicable to all cases of enteritis. I will therefore 



* The vermicular or worm-like motion of the intestines. 

 t The name given to congestion of blood in a part, from whatever cause. 

 X The circulation of venous blood derived from the abdominal organs through 

 the liver. 



