562 DISEASES OF THE EYES. 



cataract is inadmissible in the lower animals ; total blindness 

 being preferable to imperfect vision. 



Again, cataracts are described by the terms hard and soft. 

 Hard cataract is that commonly seen in the horse ; in the dog 

 soft cataract is generally met with ; it is a very common disease 

 in this animal, and is not preceded by any signs of inflammation. 

 It presents in its earlier stages a glistening tendinous aspect, 

 and a stellate appearance, resembUng a healthy lens made 

 opaque by the action of re-agents. The lens seems larger than 

 natural, and the pupil is generally dilated. 



Pet dogs that are over-fed, especially those which are fond 

 of sugar, frequently become blind from cataract. I have known 

 some cases apparently recover under a more healthy regimen, 

 and when compelled to take exercise, but ordinarily the lens 

 assumes the appearance of broken spermaceti. 



Spurious or false cataracts, so called in contra-distinction 

 to opacities of the lens, consist in opaque deposits of lymph, 

 blood, or pus on the anterior capsule, obstructing the pupil. 

 They may originate in severe traumatic ophthalmia, or they 

 may co-exist with true cataract, and arise from the same cause. 

 As a medico-legal question, the time necessary for the formation 

 of cataract becomes a subject of great importance. The case of 

 Lord Eandolph Churchill versus Day has an important bearing 

 upon it, as well as upon the liability of veterinary surgeons. — 

 See Veterinarian, 1871. 



Usually cataract is only completely developed after repeated 

 attacks of periodic ophthalmia, and in a period of time varying 

 from two to twelve months ; but there are cases where one 

 attack is sufficiently severe to destroy not only the transparency 

 of the lens, but the integrity of the whole organ of vision ; and, 

 to state what has happened in my own experience, a fully 

 formed cataract has been developed in ten days from the 

 commencement of an attack of ophthalmia ; the opacity of the 

 anterior portion of the eye being removed to such an extent 

 as to allow the cataract to be plainly visible. Such an instance 

 as this is rare. 



I have already stated that cataract in the horse may proceed 

 fi-om other causes than inflammation, and it will be well to 

 bear this in mind, should an action at law, similar to the one 

 already quoted, be raised at some future time. 



