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DISEASES OF THE CONJUNCTIVA. 



Conjunctivitis. — Inflammation of the mucous membrane 

 lining the eye lids and reflected over the eye ball around the 

 cornea. 



Causes. — 1. Mechanical and chemical irritants. — Small 

 seeds, pieces of hay, straw, glumes, wheat or barley beards, 

 small insects, coal dust and other kinds of dust, sand, hair, 

 smoke, entropium, parasites — all foreign bodies that act as 

 mechanical or chemical irritants may produce conjunctivitis. 

 Not infrequently has the writer observed this disease in a 

 very severe form, resulting from injudicious and ignorant ap- 

 plication of caustic and blistering salves, liniments or quack 

 eye washes. Striking the animal in the eye with a whip, or 

 stick; bruising or wounding the eye lid or parts near the 

 eye may excite inflammation in the conjunctiva. Cold, sharp 

 or excessively dry winds may also cause it. 



2. It is associated with other diseases, as — ulceration of 

 the cornea, periodic opthalmia, occasionally with Texas 

 fever and anthrax, influenza, strangles (distemper in horse), 

 rinderpest, and, now and then, in the course of other infec- 

 tious diseases; often it is associated with catarrhal inflam- 

 mation of the mucous membrane of the nasal passages, 

 sinuses of the head and of the lachrymal canal and ducts. 

 Inflammation of the conjunctiva and the cornea is quite 

 often observed in sheep when they are affected with "head 

 scab," or parasitic skin disease, confined to the short wool 

 regions of the sheep. Conjunctivitis is also associated with 

 sheep pox. Cattle are attacked by an enzootic inflammation 

 of the conjunctiva and cornea, which is considered in detail 

 under diseases of the cornea. Diptheritic conjunctivitis ap- 

 pears in fowls. 



Symptoms. — On the irritated and inflamed spot of 

 the conjunctiva there will be red streaks of strongly 

 congested blood vessels, the mucous membrane will 



