EXAMINATION OF THE DIGESTIVE APPARATUS 17 



and reaches the stomach at the left side. The width of the oesophagus is 

 not regular in its entire length, being narrower at the region of the pharynx 

 and at the cardiac and just before it unites with the stomach. 



The oesophagus is examined externally by the hand (palpation), 

 or internally by the pharyngeal sound or probang, and we may find trau- 

 matisms, tumors, foreign bodies (pieces of bone, wood, large pieces of food) 

 which become lodged in the oesophagus generally just beyond the 

 pharynx in the region of the neck, where they can be easily felt by the 

 hand. The thyroid gland is sometimes enlarged from local inflamma- 

 tion, struma, or carcinoma and care must be taken not to mistake this 

 for a foreign body. Very frequently we find the lymphatics of this region 

 are enlarged. Carcinomas or sarcomas are sometimes found along the 

 course of the oesophagus. 



The introduction of the laryngeal probang is comparatively easy 

 in the dog. The best probang is one less than the size of the little finger 

 and it must not be too flexible, the length should be from 20 to 30 cm.; 

 this size, of course, is for the ordinary sized dog; in very small animals 

 the ordinary sized urethral catheter can be used. Care must be taken 

 to have the probang perfectly smooth and uniform in diameter. If the 

 probang is very stiff it may be made more flexible by rubbing it briskly 

 with a towel or putting it in warm water for a few seconds. The 

 method of introducing the probang is as follows: The mouth is held open 

 as described on page 12; the head is extended and it is introduced along 

 the upper wall of the throat, keeping it high up so as to avoid the larynx. 

 If the probang should slide into the trachea instead of the oesophagus and 

 cause dsypnoea, the instrument must be instantly withdrawn. The 

 animal will attempt to swallow it, but that will assist the sounds. It will 

 glide along easily until the obstruction is reached, or glide directly into 

 the stomach. In cases where there is a foreign body in the oesophagus the 

 probang will come against it, preventing the instrument going any 

 farther. Great care must be taken at this juncture not to push the pro- 

 bang too hard as it may lacerate the walls of the oesophagus, particularly 

 if there is a stricture or a tumor; or if it is a foreign body, it may cause it 

 to be more firmly imbedded or the probang may rupture (perforate) the 

 w^alls of the oesophagus. 



Examination of the Stomach. 



Baum, who has made a careful study of the position of the dog's 

 stomach, finds when the stomach is filled with food, its outlines can be 

 easily recognized by palpation (Fig. 7). It lies in the left side of the 

 abdominal cavity, the inferior portion resting on the liver and the ante- 

 rior portion against the diaphragm, the left surface going toward the 

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