364 Veterinary Medicine. 



and the emanations from certain medicines, iodine, chlorine, 

 bromine, formaline, turpentine are strongly irritant. 



Exposure in a cold draught, or in a blast of cold rain or hail, 

 or even to a cold dry wind, in the case of hunting dogs working 

 much in water, are potent factors. 



The glare of the sun through a window at the front of a 

 stall, or from a white surface of snow, ice or water or even from 

 white sand, lime or clay is an active cause. The overdraw check 

 exposing the eyes directly to the sun is often injurious. We 

 must include the irritations caused by the filaria lachrymalis and 

 by various lesions already described — trichiasis, entropion, ectro- 

 pion, stenosis of the lachrymal duct, etc. 



In certain animals a distinct predisposition exists, often as the 

 result of a previous attack, and such are readily attacked under 

 slight disturbing causes. 



It should not be forgotten that hyperaemia and even inflam- 

 mation of the conjunctiva, often accompanies different infective 

 diseases — strangles, influenza, contagious pneumonia, rinderpest, 

 canine distemper, etc. 



Symptoms. The discharge of tears and the closure more or 

 less complete of the eyelids are among the earliest and most 

 marked symptoms. The general conjunctiva is congested and 

 that on the inner side of the lids especially, so as often to 

 hide the individual vessels, while on the sclerotic portion they 

 usually remain distinct, tortuous and freely movable with the 

 mucosa upon the sclera beneath. The membrane is more or less 

 infiltrated, swollen and opaque. In two or three days this has 

 increased so that the lids are visibly swollen, and completely 

 closed, or the paw is projected over the cornea. The discharge 

 has become milky or flocculent, and mats the cilia together,' or 

 holds the eyelids closed. Unless the cornea has been directly 

 ibjured it usually remains clear, and there is no photophobia 

 nor contraction of the pupil. The lids, however, are tender and 

 nervous animals show active resistance to any attempt to ex- 

 amine the eye. In aggravated cases a free muco-purulent dis- 

 charge takes place, and the red, swollen mucosa projects 

 between the eye and the tarsus, constituting chemosis. In such 

 circumstances the inflammation may extend to the cornea causing 

 opacity and photophobia or to the iris and choroid or other 

 deep-seated parts. 



