DISEASES OF HORSES 359 



over the eye are important, while cleanliness, warmth, dryness, and 

 rest are equally demanded. If the patient is strong and vigorous, a 

 dose of 4 drams of Barbados aloes may be given, and, if there is any 

 reason to suspect a rheumatic origin, one-half a dram powdered col- 

 chicum and one-half ounce salicylate of soda may be given daily. 

 Locally, the astringent lotions advised for external ophthalmia may 

 be resorted to, especially when the superficial inflammation is well 

 marked. More important, however, is to instill into the eye, a few 

 drops at a time, a solution of 4 grains of atropia in 1 ounce of dis- 

 tilled water. This may be effected with the aid of a soft feather, and 

 may be repeated at intervals of ten minutes until the pupil is widely 

 dilated. As the horse is to be kept in a dark stall, the consequent 

 admission of light will be harmless, and the dilation of the pupil 

 prevents adhesion between the iris and lens, relieves the constant 

 tension of the eye in the effort to adapt the pupil to the light, and 

 solicits the contraction of the blood vessels of the eye and the lessen- 

 ing of congestion. Should atropia not agree with the case, it may be 

 replaced by cocaine in 4 per cent solution. Another local measure 

 is a blister, which can usually be applied to advantage on the side 

 of the nose or beneath the ear. Spanish flies may be used as for ex- 

 ternal ophthalmia. In very severe cases the parts beneath the eye 

 may be shaved and three or four leeches applied. Setons are some- 

 times beneficial, and even puncture of the eyeball, but these should 

 be reserved for professional hands. The diet throughout should be 

 easily digestible and moderate in quantity bran mash, middling, 

 grass, steamed hay, etc. 



Even after the active inflammation has subsided the atropia 

 lotion should be continued for some weeks to keep the eye in a state 

 of rest in its still weak and irritable condition, and during this period 

 the patient should be kept in semi-darkness, or taken out only with 

 a dark shade over the eye. For the same reason heavy drafts and 

 rapid paces, which would cause congestion of the head, should be 

 carefully avoided. 



RECURRENT OPHTHALMIA (PERIODIC OPHTHALMIA, OR MOON- 

 BLINDNESS ) . 



This is an inflammatory affection of the interior of the eye, in- 

 timately related to certain soils, climates, and systems, showing a 

 strong tendency to recur again and again, and usually ending in 

 blindness from cataract or other serious injury. 



Causes. Its causes may be fundamentally attributed to soil. 

 On damp clays and marshy grounds, on the frequently overflowed 

 river bottoms and deltas, on the coasts of seas and lakes alternately 

 submerged and exposed, this disease prevails extensively. Other in- 

 fluences, more or less associated with such soil, are potent causative 

 factors. Thus damp air and a cloudy, wet climate, so constantly as- 

 sociated with wet lands, are universally charged with causing the dis- 

 ease. These act on the animal body to produce a lymphatic consti- 

 tution with an excess of connective tissue, bones, and muscles of 

 coarse open texture, thick skins and gummy legs covered with a pro- 

 fusion of long hair. 



