(ESOPHAGEAL OBSTRUCTIONS. 153 



potatoes, turnips, carrots, cabbage-stalks, beetroots, etc., which, whether 

 shced or not, are swallowed gluttonously. Not having been sufficiently 

 comminuted, and being of larger size than the oesophagus can readily 

 accommodate, they become arrested at some point between the com- 

 mencement of the oesophagus or a few inches behind the pharynx, or 

 just in front of the point of entry of the gullet into the stomach. The 

 latter is the commonest position, though not infrequently the obstruction 

 occurs in the intra-thoracic portion. 



It may occur in the stable, but is commoner in animals which, having 

 broken loose, have entered orchards, gardens or potato or turnip fields 

 and attempted to swallow apples, cabbages, potatoes, etc., found there. 



In sheep, obstruction of the oesophagus is due to similar causes, but 

 in their case the above-mentioned objects are replaced by small wild 

 apples, turnip shells, Jerusalem artichokes, horse-chestnuts, carrots, etc. 



The symptoms may be divided into general and local. 



General symptoms. As soon as the foreign body becomes fixed in 

 position, the animal begins to make exceptional efforts to swallow. The 

 head is extended on the neck, and the oesophagus and the muscles sur- 

 rounding the trachea are violently contracted. These efforts proving 

 fruitless, feeding is necessarily stopped, and the animal at once appears 

 slightly anxious. 



Very soon afterwards salivation sets in, saliva being continuously 

 secreted. If the obstruction is total, the saliva cannot be swallowed, 

 and is either returned in quantities by antiperistaltic movements or 

 escapes in frothy filaments from the mouth. 



Tympanites is not long in appearing. It is progressive, and results 

 both from arrest of eructation and from continued fermentation in the 

 rumen. It may eventually come to a standstill, or may continue and 

 threaten to produce asphyxia. 



Local symptoms. The local symptoms are difficult . to appreciate, 

 except in cases of cervical obstruction. Sometimes the foreign body 

 produces a local swelling, which changes the outline of the jugular 

 farrow, most frequently on the left side. In many cases it can only 

 be detected by manipulating the parts between the trachea and the 

 lower surface of the cervical vertebrae. When the obstruction is within 

 the thorax, the probang alone can detect its position. 



Diagnosis. The diagnosis is usually easy. The history and the 

 observed symptoms are often very clear, and the suddenness with which 

 the obstruction has made its appearance prevent the condition from 

 being confused with dilatation or stricture. 



The prognosis is very variable. It is often easy to remove the 

 obstacle ; in other cases intervention is difficult, and death may occur 

 rapidly. 



