380 
ON PERIODICAL OPHTHALMIA. 
I do not presume to have equal discernment and talent with 
our worthy Professor; but I certainly cannot see much analogy 
between ophthalmia in the horse and gout in the human subject, 
unless it is in the translation of the disease from one organ to the 
other, and the hereditary predisposition, the latter of which Pro¬ 
fessor Coleman, I believe, denies, saying no disease can be called 
hereditary. It is true, the colt does not come into the world 
with ophthalmia ; but he brings the development, lineament, 
and outline of structure of his parents; and it is in the pecu¬ 
liarity of structure of the various parts of the body that predis¬ 
position to disease exists. It is said to resemble gout in making 
its attack at night, in disappearing after an uncertain duration, 
and returning at irregular intervals. But it will be frequently 
found, should attention be attracted early to the eye, that the 
organ manifests a degree of irritability for a day or two previous 
to the strong inflammation announced by the groom on the 
morning he first discovered anything wrong in the eye. On 
the first attack of gout, paroxysms of pain and fever occur daily, 
at noon, for a short time, when it altogether disappears, and the 
patient experiences nothing more of it for perhaps two or three 
years: but this is not the case with ophthalmia in the horse, for 
although the inflammation of the conjunctiva does often rapidly 
subside, still the disease does not entirely leave the internal 
structure of the organ, as the partially contracted pupil and pro¬ 
jection of the haw more or less over the cornea are sufficient to 
prove ; nor do I believe the horse is ever entirely free from pain so 
long that light is recognized by the affected eye. 
It appears to me, that when an acute inflammation has existed 
in the more delicate structures of the eye, so much derangement 
or disorganization is generally produced as to preclude a complete 
resolution of the internal inflammation; consequently, a predispo¬ 
sition to a return of the inflammation to the acute form ever after¬ 
wards exists. 
It does occasionally, although not frequently, happen, where 
the disease has appeared in both eyes, that on the one becoming 
dark from the formation of cataract, the other does not ex¬ 
perience another paroxysm of acute inflammation for several years, 
or for the remainder of life. A grey half-bred stallion, near to 
this place, lost one eye at five years old, the other remained free 
from disease until last year, when he lost it from an acute internal 
inflammation of that organ ; and he is now twelve years old. 
The periodical ophthalmia does not commence in the conjuncti¬ 
val membrane, as some have stated : it is an internal inflammation 
from the first. The retina is evidently affected previous to the 
