267 



Treatment is not satisfactory, but is larcjely the same as for common 

 internal ophthalmia. Some cases, like rheumatism, are benefited by 

 scruple doses of powdered colchicum and 2 dram doses ot salicylate of 

 soda twice a day. In other cases with marked hardness of the globe of 

 the eye from intraocular effasion, puncture of the eye, or even the exci- 

 sion of a portion of the iris, has helped. During recovery a course of 

 tonics (2 drams oxide of iron, 10 grains nux vomica, and 1 ounce sul- 

 phate of soda daily) is desirable to invigorate the system and help to 

 ward off another attack. The vulgar resort to knocking out the wolf teeth 

 and cutting out the haw can only be condemned. The temporary re- 

 covery would take place in one or two weeks though no such thiug had 

 been done, and the breaking of a small tooth, leaving its fang in the 

 jaw, only increases the irritation. 



CATAEACT. 



The common result of internal ophthalmia, as of the recurrent type, 

 maj^ be recoguized as described under the first of these diseases. Its 

 offensive appearance may be obviated by extraction or depression of 

 the lens, but as the rays of light would no longer be properly refracted, 

 perfect vision would not be restored, and the animal would be liable to 

 prove an inveterate shyer. If perfect blindness coutiuued by reason of 

 pressure on the nerve of sight, no shying would result. 



PALSY OF THE NERVE OF SIGHT — AMAUROSIS. 



The causes of this affection are tumors or other disease of the brain 

 implicating the roots of the optic nerve j injury to the nerve between 

 the brain and eye; and inflammation of the optic nerve within the eye 

 (retina), or undue pressure on the same from dropsical or inflammatory 

 effusion. It may also occur from overloaded stomach, from a profuse 

 bleeding, and even from the pressure of the gravid womb in gestation. 



The symptoms are wide dilatation of the pupils, so as to expose fully 



the interior of the globe, the expansion remaining the same inlight and 



darkness. Ordinary eyes when brought to the light have the pupils 



suddenly contract, aud then dilate and contract alternately until they 



adapt themselves to the amount of light. The horse does not swerve 



when a feint to strike is made unless the hand causes a current of air. 



The ears are held erect and turn quickly toward any noise, and the 



horse Kteps high to av^oid stumbling over objects which it can not 

 see. 



Treatment is only useful when the disease is symptomatic of some re- 

 movable cause, like congested brain, loaded stomach, or gravid womb. 

 When recovery does not follow the termination of these conditions, ap- 

 ply a blister behind the ear and give one-half dram doses of nux vomica 

 daily. 



