194 GUTTA SERBN'A. — GLAUCOMA. 



nary occurrence, and knoMii by us all to constitute the common termina- 

 tion of periodical oplithalniia, I should say that the unusually lucid and 

 healthy aspect which every other part of the eye presents is our best 

 diagnostic sign ; the shghtest indication, however, or the slightest suspicion 

 of prior or present inflammation, being a reason for coining to a different 

 conclusion. As to the period of time a cataract of this species, supposing 

 it to be membranous, would require for its formation, I should apprehend 

 that its production might be, as its disapjDearance often would seem to be, 

 the work of a very short interval, perhaps not more than five or six days.' 

 As to the cause and treatment of it, we are at present completely in the 

 dark. If it does not soon disappear, the hydriodate of potash administered 

 internally might offer the best prospect of success. 



AMAUROSIS, OR GUTTA SERENA. 



Another species of blindness, and of which mention was made when de- 

 scribing the retina, is Gutta Serena, commonly called glass eye. The pupil 

 is more than usually dilated : it is immovable, bright, and glassy, and the 

 animal is totally blind. This is palsy of the optic nerve, or its ex- 

 pansion, the retina. It may be produced by several causes, such as 

 from a blow on the head, internal haemorrhage, pressure, the result of 

 tumours, or effusion upon that particular part of the brain from whence 

 the optic nerves arise, from some disease of the retina itself, or as the re- 

 sult of debilitating diseases. The treatment of Gutta Serena is quite as 

 difficult as that of cataract. We have heard of successful cases, but we 

 never saw one ; nor should we be disposed to incur much expense in endea- 

 vouring to accomplish impossibilities. If it proceed from injuries such as 

 blows, &c., warm fomentations should be employed and setons inserted, 

 laxative medicines being given ; if from debility we should allow nutritious 

 food, and give vegetable and mineral tonics. If we succeed it must be by 

 constitutional treatment. As to local treatment, the seat of disease is out 

 of our reach. 



GLAUCOMA. 



This is a disease occasionally met with as a termination of ophthalmia, 

 and kno'wn by the name of green cataract ; but it is much more frequently 

 met with as a result of age in very old horses. On examination the pupil 

 will be found dilated, and the interior of the eye presenting a peculiar 

 sea-green appearance, the animal being blind. It is a diseased condition 

 of the vitreous humour, and admits of no relief. 



DISEASES OF THE EAR. 



Wounds of the ear are usually the consequence of careless or brutal 

 treatment. The twitch may be applied to it, when absolute necessity re« 

 quires this degree of coercion ; but troublesome ulcers and bruises have 

 been the consequence of the abuse of this species of punishment, and more 

 especially has the farrier done irreparable mischief when he has brutally 

 made use of his plyers. 



These bruises or wounds will generally — fortunately for the animal, and 

 fortunately, perhaps, for the brute that inflicted the injury — speedily heal ; 

 but occasionally sinuses and abscesses will result that bid defiance to the 

 most skilful treatment. A simple laceration of the cartilage is easily 

 remedied. The divided edges are brought into apposition, and the head is 

 tied u.p closely for a few days, and all is well ; but, occasionally, ulceration 

 of the integument and cellular substance, and caries of the cartilage, will 

 take place — deep sinuses will be formed, and the wound will bid defiance 



