218 
THE VETERINARY SCIENCE 
offspring of sire or dam which have been subject to moon 
blindness will have a predisposition or tendency to develop it. 
Symptoms. — These are generally well marked and con- 
sidered in conjunction with the family history, usually give 
sufficient reason for coming to a conclusion that moon blind- 
ness is the trouble. 
A horse may be put in the stable after work at night, 
apparently in his usual health. By morning the eyes are 
running water, are apparently very weak and partially closed. 
One or both eyes may be affected and these symptoms may 
change from one eye to the other. The disease develops 
rapidly, so that in two or three days the affected eye becomes 
still weaker and assumes a yellowish or reddish appearance. 
At this stage there is great difficulty to see, yet in two of 
three days more the eye will have returned to its natural con- 
dition, the only outward symptom being a slight dullness. 
In the course of from three to six months these symptoms 
return and this time may effect either or both eyes. The 
attacks are periodic in this manner, each attack leaving the 
.eye in a more weakened state and more blurred, until in 
from one to three years — cases vary — total blindness is the 
result. 
First attacks may easily be mistaken for simple inflam- 
mation, but the persistent repetition of these is evidence of 
periodic ophthalmia. 
Treatment. — Treatment in the majority of cases termin- 
ates unsatisfactorily as there is grave danger of blindness in 
the end. Unless you make up your mind to drive a blind 
horse it is better to part with him as soon as the symptoms 
are such as to leave no doubt that he is affected by it. 
The progress of the disease may be arrested by bathing 
well with new milk and applications of the eye wash in and 
around the eye twice a day. This checks the inflammation 
and will enable him to retain the sight for a longer period. 
It finally, however, terminates in cataract, which, of course, 
renders him unable to see. 
Should there be a great deal of irritation it may be well 
to bleed from the vein below the eye. This is, generally, not 
so effective as in simple ophthalmia. 
3. Cataract. 
The pupil or black spot in the centre of the eye is a sort 
of window for the purpose of admitting light, so that the 
