552 DISEASES OF THE EYES. 



ball, the border of the eyelid remaining in its proper position, 

 which circumstance constitutes the distinction between it and 

 entropium. Distichiasis is the converse of trichiasis. 



Trichiasis is of frequent occurrence in dogs and cattle, but 

 seldom seen in the horse, and it admits of being relieved only 

 by the operation for entropium. 



WARTS ON THE EYELIDS. 



"Warts are not uncommon on the cutaneous surface of the 

 eyelids, or on their border. They are very often of a diffused 

 encrusted nature, and difficult to remove. 



If pedunculated, it is best to remove them by excision or 

 ligature; if broad in the base, strong acetic acid is the best 

 application. 



WOUNDS OF THE EYELIDS. 



Wounds of the eyelids are to be treated upon conservative 

 principles ; nothing must be destroyed ; the edges are to be 

 securely kept in apposition by fine silver suture wire. 



The membrana niditans is occasionally thickened by repeated 

 attacks of inflammation ; but little can be done, as it must on 

 no account be excised ; serving as it does instead of hands 

 to the horse in the removal of foreign bodies. Warts sometimes 

 grow on the membrana nictitans ; these are to be carefully 

 excised with the scalpel, being first transfixed by means of a 

 suture, or the tenaculum. 



LACHRYMAL FISTULA. 



Lychrymal fistula is caused by a blow fracturing the bones 

 through which the lachrymal duct runs. 



STRICTURE OF THE LACHRYMAL DUCT. 



This is caused by thickening of its lining mucous membrane ; 

 from catarrh of the nose extending into the duct, or from the 

 specific inflammation of glanders. The tears flow over the 

 side of the face, constituting what is termed " watery eye." 



