134 DISEASES OF THE ESOPHAGUS 



(b) The sound is to be used in those cases where the 

 obstruction is located farther down the tube and cannot be 

 reached with the throat forceps. Various kinds of instru- 

 ments have been devised for this purpose. The horse catheter 

 will answer in a large number of cases. It is introduced by 

 using the mouth speculum, depressing the tongue. Haying 

 oiled the instrument, it is passed, holding it firmly against 

 the roof of the mouth and following the posterior wall of the 

 pharynx, into the esophagus. When the instrument reaches 

 the pharynx the animal will invariably swallow, which 

 greatly assists in its introduction into the esophagus. The 

 sound is then brought in contact with the object which is 

 carefully pushed into the stomach. When there is much 

 resistance and the object is firmly fixed, the catheter should 

 be removed and other methods used to dislodge it. The 

 bristle probang is often used to advantage in extracting 

 foreign bodies which do not entirely close the lumen of the 

 esophagus. It is introduced closed so that it may pass the 

 object, and then opened so that the bristles will completely 

 fill the lumen when it is withdrawn bringing the foreign body 

 out in front of it. 



(c) The act of vomiting, which is easily induced, will often 

 displace the foreign body. This is best brought about by 

 the use of apomorphin (dogs 0.0016-0.006; cats 0.001-0.003). 

 The administration of castor or linseed oil to lubricate the 

 mucous membrane will often assist in removing the obstruc- 

 tion. 



(d) Esophagotomy is performed in the following man- 

 ner: Secure the animal in the dorsal position with the 

 head extended. Clip and shave the hair over the field 

 of operation and cleanse thoroughly with antiseptic solu- 

 tions (bichlorid of mercury 1-2000; boric acid 2 per cent., 

 etc.). Under general anesthesia, using morphin (0.016-0.21), 

 ether, etc., make a skin incision over the obstructing body 

 and between the muscles, being careful to avoid the large 

 vessels of the neck. When the esophagus is exposed make 

 a longitudinal incision through it of sufficient length to allow 

 the foreign body to be removed. Care should be used to pre- 

 vent laceration of the mucous membrane. When the incision 



