This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
This disease is frequently known among horsemen as "moon eyes." It is a constitutional affection which attacks the inner structures of the eye; it is due to hereditary influence, and although the first attack may have been caused by some local injury or some other known cause, yet that is no evidence that the predisposition to the disease was not lurking in the system and the attack would have come on at some time either with or without an apparent exciting cause.
Symptoms. - The first attack may be very slight; the eye may have appeared only a little weak with a slight watery discharge for a few days and then got all right again. Another attack may come in a month, or in six months, and it will be a little worse and last a little longer. After several attacks the eye will begin to look milky while sore, but if you stand close to the horse just back of the eye and look forward through it you will see that the aqueous humor is clear and the cloudy part is back of it. - Sometimes well-advanced cases will present a yellowish deposit in the lower part of the eye.
Treatment. - The disease is incurable and will sooner or later terminate in blindness - sometimes in cataract and sometimes in amaurosis. However, treatment can be palliative, and if begun in time may prolong the eyesight several years. Very heavy feeding especially on corn, should be avoided at all times with such an animal. When the attack comes on give a dose of aloes sufficient to open the bowels; give forty grains of quinine and four drachms of nitrate of potash in feed or on the tongue three times a day for a week. Bathe the eyes for half an hour morning and night with very warm water, then apply the following: Nitrate of potash and sulphate of zinc, of each, forty grains; rain water, one pint; mix.