l52 DISEASES OF THE (ESOPHAGtTS. 



to pressure, and sometimes produces respiratory disturbance by pressing 

 on the trachea, the pneumo-gastric and inferior laryngeal nerves, etc. 



When the dilatation is intra-thoracic and the above-described symptoms 

 have been observed, the dilated spot can only be detected and localised by 

 using the probang. The greatest possible prudence, however, is required 

 in manipulating the instrument, in order to avoid rupturing the thin walls 

 of the dilated portion. 



The diagnosis is not always easy; when food is regurgitated, and 

 one finds by auscultation that the sound usually produced by the passage 

 of solids or liquids into the rumen is absent, there need be no hesitation 

 in diagnosing either a dilatation or a stricture. The clinical consequences 

 being the same, the possible error would be of little importance. 



Prognosis. The animal's life is rarely in immediate danger, but from 

 the economic point of view the prognosis is extremely grave, and it is in 

 the owner's interest to slaughter the animal as soon as possible in order 

 to avoid loss. Even in cases of dilatation in the cervical region, surgical 

 interference is not advisable. 



Treatment. As foreshadowed by what has been said, there is no 

 rational economic treatment. When the dilatation is in the cervical region, 

 one might in exceptional, cases attemjpt to restore the regular calibre of 

 the oesophagus by removing an elliptical portion of mucous membrane, 

 and bringing the muscular tissue together with sutures ; that is to say, 

 when the rupture or Assuring of the muscular coat has been accidental. 

 But as one is usually unable to remove the primary cause, to which the 

 change in the muscular tissue is essentially due, the dilatation would 

 recur without the operation having conferred any benefit. 



When an exact diagnosis has been made, the only useful indication 

 is to confine the animal to very fluid food, which will not obstruct the 

 oesophagus. Ordinary forage should be withheld. 



CESOPHAGEAL OBSTRUCTIONS. 



In this chapter we shall only consider such obstructions as occur in 

 consequence of the animal having attempted to swallow without sufficiently 

 chewing objects which become arrested in the oesophagus. 



Obstruction is termed "total" or *' partial," according as the obstructing 

 body fills the entire calibre of the oesophagus at the point of obstruction, 

 or only occupies a part of the space. Partial obstructions produced by 

 beet and turnip tops, etc., are usually but momentary ; liquids and saliva 

 are still able to pass between the obstruction and the walls of the tube, 

 and as soon as the arrested food becomes a little softened it is displaced 

 and the oesophagus again becomes patent. 



Causation. The circumstances under which this accident occurs are 

 extremely easy to understand. Obstructions are produced by apples, 



