64 CAUSES, SYMPTOMS AND TKEATMliNT Oi' 



attack the first, and then attack the second or even the third generation. 

 In such cases it is easily pioduced. Breed only from sound, healthy 

 animals. I would not breed from a horse, no difference what his con- 

 formation might be, if affected with this disease. 



Pathology. — A constitutional affection, which localizes itself in the 

 organ of vision The inflammatory stage may pass off, even without 

 remedial aid, and then it takes on ihe second stage of the disease. 



Symptoms. — Ver}' well marked in many cases, together with the history 

 of the case, the eye having been affected some time past, but got better, 

 then worse, etc. ; was taken suddenly ; increased secretions of tears ; was 

 put in the stable at night all right ; in the morning was suffering from an 

 irritation of the eye, supposed to be an injury ; the eye weak, and cannot 

 tolerate the light. Upper eyelid droops to some extent ; eyeball retracted. 

 This can be noticed especially if but one eyeball is affected ; you cannot 

 always hotice this unless you expose the animal to the light. Conjunctiva 

 reddened and congested to a considerable extent, but not so much as in 

 simple ophthalmia ; a kind of brownish-red, hazy appearance of the 

 cornea. In periodic ophthalmia, this opacity begins at the circumfer- 

 ence and radiates toward the centre. As it advances the eye loses its 

 transparency, becoming of a yellow or reddish appearance. Th« circula- 

 tion may be altered to a slight extent; may be slightly quickened; 

 animal somewhat dull, dulness not very well marked, however ; discharge 

 of tears. After a few days the inflammatory action gradually subsides, 

 the products of inflammation become absorbed, irritation gradually 

 ceases, colour changes to a grayish colour, and the eye may regain its 

 apparent natural condition, but not in all cases. It may have slight 

 opacity of the crystalline lens, and produce cataract, but this does not 

 occur from one attack. I think in most cases there is some weakness 

 remaining, although the irritation oppears to have subsided. The eye 

 may look smaller, and is more affected with the light. It will be 

 retracted in the socket. Slight change of the weather will cause a slight 

 weeping of the eye. Another peculiarity of this disease is shifting from • 

 one eye to the other, not from sympathy ; no sooner is one eye relieved, 

 than the other is attacked. In such a case you may make up your mind 

 that you have periodic ophthalmia. Apparent recovery is very rapid in 

 some cases. To all appearance the animal is perfectly sound, but it 

 comes again with greater severity, and it continues to recur at valuable 

 periods, from three days or weeks to months, or even a year, and we have 

 some cases on record of animals having one attack and never having 

 another, but there is no particular time at which it is likely to recur. 

 After cataract is formed, there may be inflammatory action in the eye, 

 but after the eye is completely disorganized, as is sometimes the case, 

 inflammation does not affect it further. As to the duration of the 

 disease, it may vary from three to four up to ten or fifteen days. It is 

 sometimes developed in the acute form, but generally in the sub-acute 

 form. An animal may suffer from one or two attacks, and appear pretty 

 well without any well marked cataract. It has been noticed that horses 

 working in coal pits, under ground in dark places, suffer frequently from 

 amaurosis, and also from ophthalmia. The mode of using being the 

 exciting cause. 



Treatment. — Is anything but satisfactory, and it sometimes grieves 

 the owner to be told that sooner or later his animal must be- 

 come blind. The irritation may be palliated by rational treatment. 

 Place the animal in a well-ventilated and darkened box ; but you 

 may have to allay irritation and keep the animal at work. Give 

 a moderate dose of purgative; it acts upon the system and allays 



