244 ANIMAL DENTISTRY. 



The first molars must be well rounded to prevent buccal 

 wounds. The bit is then kept on a straight line with the jaws 

 by means of washers fastened inside the rings. A com- 

 fortable check is used, and the horse is driven only with one 

 well mated in promptness. 



HABITUAL PROTRUSION OF THE TONGUE. 



Synonym — Tongue lolling. 



Definition — The habit of extending the end of the tongue 

 from the commissure of the mouth while driving. 



Etiology — The habit may be first acquired in an attempt 

 to protect an abrasion of the mouth from further injury, but 

 its continuation is due to the relief to the respirations. When 

 the tongue is dropped from the fauces the lumen of the 

 pharynx is increased and the respirations are facilitated suf- 

 ficiently to induce a continuation of the habit. Paralysis 

 of the tongue, in which retraction is impossible, is entirely 

 another condition, occurring as a result of progressive bul- 

 bar paralysis — a fatal disease. 



Treatment — Dental irregularities must be corrected and 

 the head while driving must be elevated with the overdraw 

 check to bring the air passages toward a straight line. The 

 mouth may be closed with a nose band attached to the bridle. 

 Attaching the check bit to the main bit by means of a flexible 

 rubber hose, will frequently prevent the habit. 



When these measures fail, amputation of the tongue is 

 the only recourse. 



OPERATION OF AMPUTATION OF THE TONGUE. 



Restraint — Lateral recumbent position under chloroform 

 anaesthesia. 



ist Step — Make a circular incision, convexity forward, 

 from the center of one border to the center of the opposite, 

 so as to make one-half of a dove-tail flap. 



