994 



DISEASES AND THEIR TREATMENT. 



preparation lias proved fui- me very efficient in reducing local 

 inflammation. 



Specific, or Periodic Ophthalmia, 



Is the most severe afl^^ection to which the horse's eye is liable, and 

 is very common in this country. The parts principally and pri- 

 marily involved are the internal structures of the eye, and the 

 changes which occur vaiy in degree to the severity of the attack. 

 Causes. — The great cause of this affection can be traced to an 



hereditary predispo- 

 sition, always ready 

 to burst forth when 

 exposed to certain ex- 

 citing causes, such as 

 injui-ies of any kind, 

 as before explained, 

 being kept in very 

 dark and ill-venti- 

 lated stables, and then 

 suddenly exposed to 

 the glare of a hot 

 sun; and, like simple 

 ophthalmia, it may fol- 

 low continued expos- 

 ure to cold. 



Symptoms. — 

 Among the first 

 symptoms is a watery discharge from one or both eyes, and on be- 

 ing exposed to the sunlight he exhibits a peculiar uneasiness, with 

 a partial closure of the affected eye. As the disease advances, the 

 eyelids become swollen, and if turned upward, the conjunctiva 

 appears reddened and injected ; the eye looks smaller, and retracted 

 into its socket; the interior of the eye reveals a peculiar muddy 

 or turbid appearance, showing floating flakes, and a yellowish or 

 whitish deposit at the bottom of the chamber. Fig. 860 is designed 

 to show, on an enlarged scale, something of this change. The 

 symptoms are very like tho.se of simple ophthalmia, and often leads 

 to the supposition that the eye has received a blow or other injury. 

 The above symptoms become more and more aggravated, and 



Fig. 85S. 



-Physiological papillae, as seen with the 

 ophthalmoscope. 



