DISEASES OF THE OX AND SHEEP. 609 



is listless, avoids the light, stands apart from its fellows in the 

 field ; the olosed eyelids twitch and sometimes swell, and give out 

 a profase discharge of tears, which become thick and viscid. 



The eye itself may be exposed by placing the forefinger of the 

 left hand firmly upon the eyebrow and pulling the skin upwards, 

 and with it the upper eyelid, while with the right thumb the 

 lower eyelid is drawn downwards. The separation of the eyelids 

 gives rise to a fresh outpouring of tears. It will generally be 

 found that the cornea, being exposed in this manner, is seen to 

 be opaque, and of a bluish-grey colour. Should a wheat-husk 

 or other object be observed, it may be carefully removed with 

 the corner of a handkerchief. Sometimes a rather sharp-pointed 

 instrument may be useful in the hands of a veterinary surgeon 

 for the removal of the foreign body. A suitable lotion will be 

 requisite. 



The conjunctiva, a membrane covering the eye and lining the 

 eyelids, is liable to be afi'ected with a frequently recurring inflam- 

 mation of a destructive kind, and as a result of this inflammation 

 the eyesight may be rapidly destroyed. The lids may adhere to 

 the eyeball, and their movements maybe impeded. This kind of 

 blindness may come on in sheep suffering from sheep-scab, and in 

 countries wherein blindness of this character occurs frequently, 

 the shepherds are wont to keep in their pockets a piece of hard 

 wood, well polished, and shaped like a very small paper-knife. 

 This instrument is introduced under the lid, when it is thought 

 necessary so to do, perhaps at the outer angle of the eye, and by 

 this means the adhesion is forcibly broken down. Then the eye 

 is washed with a decoction of mallows or poppyheads, or perhaps 

 a Httle oil is put in. 



This disease, ophthalmia, which we are now considering, 

 frequently assumes an epizootic character among sheep, and 

 sometimes also in cattle. This form of the malady is very 

 generally known as " the blind." As a set-off" against this 

 liability to " the blind," it is to be borne in mind that sheep, 

 and, indeed, oxen and swine also, only rarely suff'er from 

 cataract, a disorder which, in the case of the horse, is one of 

 the most commonly met with of all the derangements of the 

 eye. This disease, " the blind," most especially affects the 

 young sheep of flocks kept in exposed situations. Unless the 

 malady be arrested at an early stage, the afflicted animals sink 



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