268 OPHTHALMIA. 



in red lines extending over it. If this state of the pupil is not 

 present at the first, the continuation of the affection for several 

 days commonly produces it: now and then, the humours of the 

 eye are seen to exhibit a reddish tinge ; but this is not frequent. 

 The causes of the affection are various : excitements of any kind, 

 as violent exertions, heat and cold alternating in extreme degrees 

 occasion it : thus I have seen it follow from plunging into water 

 when the dog has been very hot, and not accustomed to the change. 



Ophthalmia is also occasioned by external violence, and by ir- 

 ritating matters settling within the eye; or stings, &c. without. 

 These cases are known usually by one only being aflfected ; but I 

 have seen pointers, setters, and spaniels, suddenly thus seized after 

 hunting in cover, from some poisonous herb ; in which case it is 

 seen in both eyes. Thorn wounds, scratches from cats, &c., are 

 productive of it ; but it is commonly confined to one eye. 



The treatment is not dissimilar in principle in all these cases : 

 should the inflammation be very considerable, bleed, purge, and 

 keep low : foment the eyes with an infusion of poppy heads, until 

 the light does not distress the dog, when apply the following wash 

 several times a- day : — 



Superacetate of lead (sugar of lead) half a drachm 



Rose water 6 ounces. 



When the inflammation is somewhat lessened, use the fol- 

 lowing: — 



Sulphate of zinc 1 scruple 



A weak infusion of elm bark 6 ounces 



Brandy 1 tea-spoonful. 



Sometimes the following has moderated the irritation when 

 other applications have failed : — 



Tincture of opium half a drachm 



Infusion of green tea 4 ounces. 



All exposure to strong light, or other sources of irritation, as 

 foul housing, &c., should be avoided. In very bad cases, I have 

 sometimes scarified the insides of the eyelids, and even the white 



