444 Veterinary Medicine. 



Treatment should be first directed toward the elimination of 

 any poisons, such as lead or tobacco, which may act as a causa- 

 tive factor. Saline laxatives and in chronic cases potassium 

 iodide would be indicated. Every attention should be given to 

 the maintenance'^of good general health, and in acute attacks, 

 local bleeding and counter-irritation- may be resorted to. 



ATROPHY. PARAI^YSIS OF THE OPTIC NERVE. AM- 

 BI^YOPIA. AMAUROSIS. 



Definition. Horses, dogs, cattle, sheep. Amblyopia, Amaurosis. Causes: 

 retinal paresis from brilliant light, of cerebral ganglia, snow blindness, 

 poisons, lead, opium, atropine, lolium, tobacco, carbon bisulphide', crypto- 

 gams, mushrooms, "loco " plants, carbon monoxide, illuminating gas, qui- 

 nine, heat apoplexy, cerebral concussion, brain parasites, exudates, pres- 

 sure, degeneration, gastric or intestinal disorder, hsemorrhage, anaemia, 

 diarrhoea, diuresis, excessive milk secretion, gestation, embolism. Symp- 

 toms : constant excessive dilatation of pupil, no response to light, brilliant 

 reflection from retina and choroid, blue or yellow, (glass eyes) ; bilateral, 

 cerebral, tract or chiasma ; unilateral, bulbar or nervous ; face without 

 expression, ears alert, head to one side, nose elevated, nostrils dilated, ox 

 and dog smell ground, slow pace, high stepping,' does not dodge a feint to 

 strike. Lesions : inflammatory exudate and retinal atrophy, congested, 

 " woolly " papilla, retrobulbar congestion or atrophy of nerve, thickening 

 of neurilemma, tumors of orbit or foramen optica, coenurus, cysts, ab- 

 scesses, cholesteatomata, psammomata, hydrocephalus, meningitis, pineal 

 h) pertrophy, cranial fractures or tumors, embolisms or aneurisms, hyper- 

 trophy of dura, apoplexy. Treatment : remove causes, laxatives, diuretics, 

 for lead, sulphuric acid and potassium iodide, darkness, extract coenurus, 

 elevate depressed fractures, ice, cold water, snow, to head, blisters, setons, 

 electricity, strychnia, remove tumors. 



Blindness without adequate, corresponding, visible changes in 

 the structure of the eye, has long been recognized in the lower 

 animals, having been observed in horses, dogs, cattle and sheep. 

 When partial it is known as amblyopia, and when complete as 

 amaurosis or blindness. The term amaurosis is, however, being 

 gradually eliminated from ophthalmological nomenclature in 

 favor of that of atrophy. 



Causes. These may be factors which act directly on the 

 retina, as the ■ intense light of the sun, of an electric, lime or 



