DISEASES AND TREATMENT OF THE HORSE 219 



imagd of objects in front of the eye may be reflected upon 

 the sensitive portions on the inside and thus carried by the 

 optic nerve to the brain. In this manner animals *are 

 possessed of the sense of sight. Should the admission of the 

 rays of light be obstructed from any cause, total or partial 

 blindness is the result, according to the degree of obstruction. 



A cataract is an opaque, pearly white deposit across the 

 pupil. It may be what is termed partial or complete for the 

 reasons above stated, and may affect one or both eyes. 



Causes. — Cataract is sometimes present at the time of 

 birth. Repeated attacks of inflammation such as in a case of 

 ophthalmia will cause it. 



Symptoms. — The white portion is quite clearly seen. 

 There is whole or partial blindness. 



Treatment. — Very little, if anything, can be done, unless 

 by an operation, and such an operation is not attended with 

 but slight success in the horse, because of the impossibility 

 to regulate the sight with glasses as is done with people. As 

 for medicine, when the cataract is well formed there can be 

 nothing given which is effective. 



It is an important matter to examine the eyes of a horse 

 carefully before purchasing him, to see that no indications of 

 cataract are present. 



4. Star Gazer (Amaurosis). 



This is paralysis of the optic nerve, the function of which 

 is to carry to the brain impressions reflected upon the retina. 



Causes. — A sudden jar or injury to the head, standing in 

 a dark stable or sudden exposure to extremely bright light 

 may paralyze this nerve. The loss of a great deal of blood 

 sometimes causes a temporary paralysis, but the sight returns 

 with the re-established circulation. 



Symptoms. — The eye has a large, glassy appearance, and 

 the pupil of the eye is very much enlarged. If taken from a 

 dark stable into the light the pupil of the eye does not close 

 up to regulate the admission of light as if it were in good 

 condition, but remains large. He generally carries his head 

 high and steps high. 



Treatment. — If the case is of long standing nothing can 

 be done for it; if the result of injury by striking the head 

 against something, or of bleeding, it can be treated success- 

 fully. Give a teaspoonful of mix vomica in the feed three 



