31 



"an oat grain in the eye" by uninformed laymen. The ab- 

 scess generally erupts or breaks open on the outer corneal 

 surface leaving an ulcer to heal by granulations forming 

 over its sides and bottom. In cattle, as a rule, the scar 

 tissue is entirely removed and the cornea becomes clear and 

 completely nonnal. However, in horses and occasionally in 

 cattle a permanent pearly white opacity remains, causing 

 partial or complete blindness. Some cases do not advance 

 to the stage of abscess formation ; in others the abscess may 

 not erupt ; while in still others the abscess may be so large 

 that when it breaks open, the pressure of the aqueous humor 

 against the remaining thin portion of the cornea will per- 

 forate it; this sudden removal of pressure on the lens may 

 rupture the capsule of the lens and permit it to escape ; the 

 entire eye is thus involved, resulting in total loss of sight 

 and of the eyeball. 



The cause of this spreading eye disease is unknown, yet 

 there are indications that point towards a germ or a micro- 

 organism as an exciting cause. Billings claims that it 

 slowly extends over a herd from one animal to another; one 

 eye may be at first affected, but in a short time the other eye 

 is attacked. According to some of the German authorities 

 the disease spreads quite rapidly — in a few days attacking 

 50 in a herd of 300; in 7 days attacking 20 in a herd of 40. 



Treatment. — Separate the sick from the healthy ; apply 

 a solution of corrosive sublimate 1 part, water 2,000 parts; 

 saturate a clean cotton cloth with the above solution and 

 adjust the cloth over the eye; keep the cloth moist with the 

 solution. During the purulent discharge from the conjunc- 

 tival sack, the eye may be washed night and morning with 

 warm water. 



ULCEK OF THE CORNEA. 



Loss of substance or destruction of a limited portion of 

 the cornea may result from the erupting of a corneal abscess, 



