DISEASES OF HORSES. 207 



19. The opthalmia, lunatic, or moon-blindness, is a very peculiar 

 disease among horses, affecting their eyes generally about their 

 full growth, but sometimes later, and seldom earlier. It is but 

 little known among mules and asses, and unknown in oxen and 

 sheep. It does not, however, appear to be a disease natural to 

 the horse, as wild, or even horses subjected to artificial restraints 

 are not observed subject to it. But among others, it is become so 

 common as to have the tendency handed down in the breed ; the 

 progeny of some stallions being more prone to it than others.— 

 It is often very sudden in its attack, the eyelids being found 

 swelled and almost closed to avoid the light ; they are also very 

 red within, and the haw is half drawn over the surface ; the tears 

 flow down the face perpetually, and the whole head is hot ; now and 

 then these appearances come on gradually. The suddenness of the 

 attack makes the complaint to be attributed to accident, as blows, 

 hay seeds within the eye, &c. and it is frequently difficult to get 

 the owner of such a horse to believe that a constitutional attack, 

 as it usually is, can come on so suddenly. Sometimes as it comes 

 on, so it goes off as quickly, the eye from being opaque and milky, 

 in twenty four hours becoming clear and almost well. When such 

 an attack has taken place, even if nothing be done, the horse 

 sooner or later amends, and the eye or eyes, for it is sometimes 

 one and sometimes both that are so attacked, become again clear 

 and well, and remain so an indefinite period, from five or six weeks 

 to as many months. Another attack, however, sooner or later 

 follows, to which others succeed, each leaving increased milkiness 

 on the outer coats, and some dimness within the pupil, either speck- 

 like or diffused ; and finally the horse becomes blind from cataract. 

 When one eye goes blind totally before the other, it is often a 

 means of preventing the future attack on the ren:iaining one ; 

 which has given rise to a custom of putting out one eye to save 

 the other, and which has succeeded. As this is a constitutional 

 disease, brought on by artificial habits, as over exertion, close 

 unhealthy confinement, and heating food ; so it is clear the abstrac- 

 tion of all these are necessary to remove the complaint, and to 

 prevent a recurrence ; but particularly the close, dark, and unven- 

 tilated state of the stable should be attended to, as well as Ihe 

 removal of the litter, which retains the volatile alkali of the urine, 

 and irritates the eyes most injuriously. The food should be mild 

 and cooling, and the exercise moderate but long continued. Under 

 the height of the attack, however, rest is advisable, with moderate 

 light, which may be still further moderated by keeping over the 

 eye or eyes a thick cloth, wet with goulard water. {Vet. Ph. 154.) 

 Sometimes one quarter of vinegar to three quarters of water has 

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