OPERATIONS ON THE (ESOPHAGUS. 369 



In ruminants the operation is performed in the standing posi- 

 tion, with the head extended and elevated on the neck. In soU- 

 peds it cannot be performed except whHe the animal is down, and 

 when the head can be placed in the proper position of extension 

 to aUow the instrument to pass beyond the elbow formed by the 

 pharynx and the oesophagus. The animal being in position, and 

 the speculum adjusted, an assistant draws the tongue out of the 

 mouth, and the operator, placed in front of his patient, passes the 

 probang through the opening of the speculum, and rapidly pushes 

 it into the mouth, resting it upon the hard palate, in order to pre- 

 vent its being displaced laterally by the motion of the tongue. At 

 the bo'ttom of the mouth the probang meets with some httle re- 

 sistance at the soft palate, but the instrument soon reaches the 

 fauces, in the pharynx, and penetrates the oesophagus. At this 

 moment possibly some resistance may be encountered, owing to 

 the contraction of the crico-pharyngeus muscle, but once engaged 

 in the oesophagus the instrument readily passes the proper dis- 

 tance downwards, according to the requirements of the case. If 

 the object in view is to relieve tympanitis, and a true catheter, 

 tube, or stomach pump or hollow probang has been used, the 

 gases will find a means of exit as soon as the instrument has 

 penetrated the stomach. 



If the catheterism has been performed for the displacement of 

 foreign bodies, the resistance they offer to the pressure of the 

 probang must be overcome by a steady, and, at times, quite a 

 powerful pressure of the instrument, caution being always neces- 

 sary to avoid causing laceration of the wall of the passage. When 

 the obstruction is even but sHghtly loosened, its complete dis- 

 lodgment often follows from the mere unassisted contraction of 

 the oesophageal muscles. Caution and gentleness must not be 

 overlooked even in the mere withdrawal of the probang. It 

 should be practiced as a maxim, indeed, that whatever instrument 

 may be, for any purpose, made use of, not alone in the propulsion 

 of the intruding body in these cases, the operator must never re- 

 mit his caution and gentleness, nor lose sight of the fact of the 

 natural liabUity to accident always accompanying surgical in- 

 terference with the organs and tissues having their place in the 

 interior regions of the animal organism, and not cognizable by 

 the eye. Serious accidents have been recorded as resulting from 

 a lack of care and attention in the manner of withdrawing the in- 



