190 SPECIFIC OniTIIALMIA 



tei'istic in specific ojilithalmia ; tlie iris remains clear and briglit, and tlie 

 lens is unaffected. 



This common inflammation is generally sudden in its attack. It is 

 occasionally connected -Rath an attack of catarrh or cold ; but it is as often 

 unaccompanied by this, and depends on external irritation, as a blow, or 

 the presence of a bit of hay-seed or oat-husk within the lid, and towards 

 the outer corner Avhere the haw cannot reach it : therefore the lids should 

 always be carefully examined as to this possible source of the complaint. 

 The lids will be found swollen, and the eyes partially closed, with more or 

 less weeping, the inner surface of the eyelids red and tumid, and the cornea 

 will either appear bright or cloudy, according to the extent of the injury. 

 It not unfrequcntly happens when the injury has resulted from the lash 

 of a whip, or a thorn, that the conjunctival membrane becomes lacerated ; 

 and sometimes the injury extends to the cornea. 



Our first object by way of treatment should be to ascertain the cause of 

 the mischief hy carefully examining the eye and the removal of any of- 

 fending object. The animal should be placed in a cool but somewhat dark 

 box, the eye should be bathed with warna water, laxative medicine given, 

 and the animal kept on soft diet. If the inflammation be very acute, blood 

 may be taken from the facial vein. In a few days the inflammation will 

 generally subside, and then a weak solution of sulphate of zinc may be 

 applied. When the acute inflammation has passed away, the cornea is 

 sometimes left very tense and cloudy : we may now apply stimulants to its 

 surface in the form of solution nitrate of silver (gr. ^dii to ^j aqua distillata), 

 at first injected for twenty-four hours, and then cgasing for two or three 

 days, and again employing it if necessary. When we get granulations on 

 the cornea as the result of lesions, nitrate of silver must be applied in 

 its pure state. 



SPECIFIC OPHTHALMIA, OR MOON-BLINDNESS. 



In this we have a far more formidable and destructive disease than the 

 one just described ; it is, indeed, one of the opprobia of veterinary science, 

 utterly baffling all its resources and running its course erratically, mdeed, 

 but most surely aiid destructively. The aqueous humour often loses 

 its transparency — even the iris changes its colour, and the pupil is exceed- 

 ingly contracted. Indeed the term Iritis, or inflammation of the iris, will 

 convey a much more intelligible idea of the disease than any other, for it 

 is this, with the other internal tissues of the eye, that especially suffer from 

 its devastations. The external parts of the eye are comparatively but 

 little implicated, and suffer only in a comparative degree ; but see its effects 

 on the ii'is, which gives the colouring and beauty to the eye, — its brilliancy 

 is lost, its texture is broken down, it is a dark, discoloured curtain ; look at 

 the symmetrical pupil with its full rounded edge, — it is lacerated and torn, 

 jagged and disfigured, as if mechanical destruction had torn it ; then its 

 centre ornament, the beautiful lens, transparent as a crystal, clear as a 

 diamond, is become disorganised, crushed, discoloiu'ed, a shapeless opaque 

 lump, instead of the bright transparent conductor, — the light of heaven 

 can no longer permeate it, and total blindness is the result. 



The veterinary surgeon has now an obstinate disease to combat, and one 

 that will generally maintain its gi'ound in spite of all his efforts. For three, 

 or four, or five weeks, the inflammation will remain undiminished ; or if it 

 appears to yield on one day, it will return in redoubled violence on the 

 next. At length, and often unconnected with any of the -means that have 

 been used, the eye begins to bear the light, the redness of the membrane 

 of the lid disappears, the cornea clears up, and the only vestige of disease 

 which remains is a slight thickening of the lids, and apparent uneasiness 

 when exposed to a very strong light. 



