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 or 

 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 



