DISEASES OF THE INTESTINES. 223 



Etiology of Colic. — Colic may be due to dietetic errors, 

 such as have been already mentioned as liable to induce 

 dyspepsia, diarrhoea, constipation, and other disordered 

 states of the system. Over-feeding, sudden changes in the 

 diet, irregularities in the dieting, taking a large amount 

 of food after a long fast, or after prolonged or severe exer- 

 tion, food of inferior or unsuitable quality, are all potent 

 agencies in the production of spasmodic intestinal contrac- 

 tion, as well as of flatulent distension, which may be asso- 

 ciated with the spasm or occur independently. 



Besides dietetic errors, there are many other causes of 

 colic. This painful affection may be due to intestinal ob- 

 struction from mechanical displacement, and change of 

 position of different parts of the intestine, or from impaction 

 of calculi or other concretions of varying composition. 



Not unfrequently colic depends upon the presence of 

 animal parasites in the bowels, and sometimes also in neigh- 

 bouring parts. Young animals esj^ecially, when badly fed 

 and attended to, are more liable to colic from this source 

 than older horses. Pain, when originating from the pre- 

 sence of worms, is usually of a recurrent type, and attended 

 with progressing debility and loss of flesh. The presence 

 of certain worms in the mesenteric arteries is, as we shall 

 see in the chapter on parasites, also said to be a frequent 

 cause of colic on the Continent, more especially in Germany. 

 This parasitic affection, which is rarely met with in this 

 country, sometimes even ends in death. Irritant poisons, 

 when ingested, produce pain, sometimes very intense. Cold 

 and damp also may cause intestinal disturbance, manifested 

 by abdominal pain. 



Lastly, as causes of colic are the group of organic diseases 

 not only of the intestine itself, but also of the peritoneum, 

 kidneys, liver, and pleura. 



Among the organic diseases which may produce colic are : 



