Etiology. Pathogenesis. 381 



and had been formed from the hairs of grains of oats. Wiesner found in a tliroe 

 months' okl foal a conerement, obstructing the terminal portion of the ileum, com- 

 posed of food particles, hairs and infiltrating lime salts. 



Fecal balls composed exclusively of feces are more rare 

 than concremeiits. The intestinal Imnen of newborn foals may 

 be obstructed by meconium (Topper). 



The lumen of the small intestines may be obturated by ani- 

 mal parasites such as ascaris, gastrus, larvae (Kater, Rexilius). 



The anterior portion of the small intestine is onl}^ rarely 

 obturated by swallowed foreign bodies (Bech, Jacobin and 

 Clare, Angebauer, authors' observation). Closure by a hem- 

 atoma formed in the intestinal wall is also quite rare (Uhlig, 

 Kitt, Schleg & Jolme). 



Obturation of the intestines of dogs is often produced by 

 foreign bodies swallowed in play or in retrieving (see page 312) ; 

 also by pieces of bone and cartilage, occasionally also b}^ hair 

 balls, lumps of feces, parasites (taenia) ; such foreign bodies 

 are much less frequently the cause of obturation in cats. 



In ruminants and hogs obturation of the intestinal lumen 

 by hair or fecal balls, or ))y swallowed foreign bodies, or by a 

 hematoma (Eber) is rare. (Fetting found in a young heifer, 

 which had died of digestive disturbances, a young cat wedged 

 in the small intestine ; Wyssmann saw a case with obturation of 

 the large intestine by masses of fibrin ; Sporer saw a case where 

 a potato had become wedged in the small intestine and one case 

 where a vegetable stem formed the impediment.) 



Pathogenesis. Foreign bodies formed in the intestines 

 (calculi), or arrived there from without, may sometimes remain 

 in a wider portion of the intestinal tract without doing any 

 harm at all. Zschokke found, in a miller's horse which had al- 

 ways been well, forty-two pounds of intestinal calculi, one alone 

 weighing twenty pounds. At other times calculi are the cause 

 of chronic intestinal catarrh (see page 340), or of intestinal 

 stenosis (see page 387). Closure of a narrow portion of the in- 

 testines is not at all rare if the bodies have been moved to such 

 places by peristalsis and have there become wedged in; the 

 closure may then be due to the foreign body alone or to it and 

 the masses of feces which accumulate at this site. 



The site of the obturation varies according to the deriva- 

 tion of the obturating body. In horses genuine calculi and con- 

 crements, also lumps of feces generally become wedged into the 

 first portion of the small colon, more rarely somewhat more to- 

 wards the anus, occasionally also into the pelvic flexure of the 

 large colon; desiccated feces (chatf) are also sometimes found 

 in the last portion of the ileum or of the duodenum which they 

 obturate rather suddenly (see page 366). The large intestine is 

 usually obturated by fecal agglomerations in dogs. In all other 

 cases (foreign bodies, intestinal parasites) obturation usually 

 occurs in the horse and in all other animals, in the small intes- 

 tines. 



