OPERATION AGAINST RETENTION CYST 441 



are flooded through the nasal chambers by a gush or two 

 from a twenty-four ounce syringe through the incision in 

 the trachea made for the trachea tube. 



Operation for Tympany of the Guttural Pouch 



In colts, the eustachian tube is sometimes possessed of a 

 congenital defect, which, although admitting air freely 

 enough into the guttural pouch, blocks the outward flow in 

 the manner of a valve. The condition, which is sometimes 

 bilateral, presents itself in the form of a more or less 

 voluminous compressible tumefaction of the parotid region. 

 If lanced the air escapes, but as soon as the wound has healed 

 the trouble recurs. 



The operation against this serious trouble consists of 

 hyo-vertebrotomy, previously described, and the obliteration 

 of the incriminated eustachian tube with a long bistoury. 

 After access to the pouch has been gained by hyo-vertebrot- 

 omy, the head is extended and the long, curved, probe- 

 pointed bistoury is passed through the tube from pouch to 

 pharynx. A careful downward sweep completes the opera- 

 tion. Permanent results depend upon permanent obliteration 

 of the tube. If the wound heals without having disarranged 

 the valve-like mechanism responsible for the trouble, the 

 operation will prove unsuccessful. 



Operation Against Retention Cyst (Atheroma) 

 of the False Nostril. 



The integument forming the superior boundary of the 

 false nostril of the horse is often the seat of a uniformly 

 characteristic retention cyst about the size of a walnut, con- 

 stituted of a well defined membranous wall enclosing a 

 gelatinous, creamy or caseous substance. 



When submitted to simple evacuation by lancing, the sac 

 refills within a relatively short time, and if attempt is made 

 to destroy the secreting membrane by injecting strong 

 caustics a threatening, acute, local reaction supervenes. 

 Several injections are required. The skin sometimes sloughs 

 through ; finally the cicatrization is exceedingly slow, and the 

 patient becomes keenly sensitive about the head. 



The only prompt curative treatment is total excision of 

 the sac, by peripheral dissection, which should be carefully 

 executed without evacuating the contents or accidentally 

 snipping the skin boundary. 



