244 '^HE FARM DOCTOR. 



tincture of (physostigma) Calabar bean, and i quart water, 

 changing twice daily ; blister the face or neck as for enzootic 

 ophthalmia. 



RECURRING OPHTHALMIA. PERIODIC OPHTHALMIA. 



MOON-BLINDNESS. 



Attacks solipeds only. 



Causes. — Hereditary predisposition ; breeding in damp, 

 cloudy, foggy, or marshy localities ; keeping in damp, close, ill- 

 conditioned stables ; the irritation about the head attendant on 

 teething; clogging the digestive organs by feeding wheat or 

 maize without salt or sulphate of soda, the presence of worms 

 in the intestines ; whatever lowers the general health, and the 

 general causes of iritis. 



Symptoms. — Like those of internal ophthalmia, with, in many 

 cases, increased tension and hardness of the eyeball, and its 

 deeper retraction into the orbit. The main difference is in the 

 liability to recur, at intervals of three weeks, a month, or more, 

 if the exciting causes have not been removed, until the subject 

 is left blind. In the intervals between the attacks the trans- 

 parent coat of the eye retains a hazy bluish cloudiness around 

 its border, the iris is wanting in its normal lustre, the anterior 

 chamber has often a slight deposit at its lower part, and the 

 upper eyelid is bent at an unnatural angle, about one-third of 

 its length from the inner angle. After two or three attacks a 

 cataract remains. 



Prevention.— Avoid, for breeding purposes, all horses belong- 

 ing to an affected family ; all localities that are damp, foggy, 

 cloudy, or relaxing ; as well as ill-appointed stables. Maintain 

 good health and condition by sound feeding, watering, housing, 

 grooming, and exercise. When threatened remove to a drier 

 and more bracing climate. 



Treatment. — As for iritis. Some cases, like rheumatism, are 

 benehted by colchicum and the free use of alkalies (carbonates 



