58 OPHTHALMOLOGY FOR VETERINARIANS 



If the case is at the point of rupture an incision 

 should be made, and, under a local anesthetic, the sac 

 may be cureted and a solution of nitrate of silver applied. 

 It is well to establish the drainage canal if possible, and 

 pass through it a solution of argyrol, then some boric 

 acid solution. Keep the sac clean and free from pus. 

 Should it become permanently or chronically affected, 

 the best thing to do is carefully to dissect out the sac. 

 This should be done during the stage of quiescence. 



Stenosis of the Nasal Duct. — This almost always ac- 

 companies the above disease, and is due to thickening 

 and adhesion of the mucous lining of the duct. In 

 man, the duct is probed from above, through the puncta 

 — usually the lower one. The point of the probe is 

 passed into the punctum in a vertical position, then, 

 placed horizontally, it is pushed through the canaHculus 

 to the bony wall, then, again in a vertical position, it is 

 gently pushed until it engages in the upper portion of 

 the duct, when it is forced firmly, but gently, downward 

 through the duct. In the animal, the probes used are 

 much larger and longer than those used in man, and, 

 instead of being inserted from above, they are inserted 

 in the outlet of the duct below, opposite the middle 

 turbinate bone in the nose. After the point of the probe 

 is engaged it is pushed upward to the sac, gently break- 

 ing up the adhesions in its course. This operation 

 should be repeated two or three times a week, accord- 

 ing to the indications. 



