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DISEASE OF THE LACHRYMAL PASSAGES*. 
By Mr. William Percivall, M.R.C.S.. Veterinary Surgeon 
First Life Guards. 
The malady familiarly known as “ a watery eye,” only now 
and then occurs in horses. I may have met with some half-a- 
dozen cases of it in my time ; some or all of which might have 
been, in days gone by, called fistula lachrymalis : an appellation 
which surgeons, better informed, of the present day, properly 
confine to a form or stage of the disease that I cannot say I ever 
had occasion to treat in my own practice. The lachrymal ap- 
paratus in animals is little subject to be out of repair. Its com- 
parative simplicity, the larger size of the passages and apertures, 
and the little irregularity which happens in the lachrymal secre- 
tion, may serve to account for this. 
In horses there seem to be three causes from which the tears, 
instead of pursuing their natural course, may overflow the under 
eyelid and trickle down the face. One is, an increase or super- 
abundance of secretion ; and this may arise either from some 
external cause of irritation, or — what is commonly the case — 
from the presence of conjunctival inflammation: hence the 
escape of tears down the face becomes one of the symptoms of 
ophthalmia. A second cause is, tumefaction of the eyelids, 
occasioning diminution of the puncta lachrymaliaj as well as, 
perhaps, interfering somewhat with the regular course of the 
tears into them. A third, and the grand cause, — it being the 
one we are to regard as constituting the disease of which watery 
eye is the sole or especial symptom, — is obstruction in the 
lachrymal passages. The nature of this obstruction — so far as 
our operations to relieve it have enabled us to judge of it — 
appears to be similar to what constitutes a stricture in the urethra 
in man ; viz. a thickening of the lining membrane in some parts 
of the passages, in consequence, as it would seem, of some prior 
or existing inflammation. That this membrane, which is of the 
mucous class, appearing indeed to be a continuation of the con- 
junctiva, is not infrequently inflamed, in its course through the 
puncta at least, we may adduce as evidence the globule of 
mucus so commonly seen lodging upon the puncta in catarrhal 
and other inflammations about the head ; and if so often inflamed 
in the puncta , no doubt, on occasions, it becomes so through its 
whole course. The common seat of obstruction — so far as our 
* Mr. Percivall’s “ Lectures on Horses’’ will be continued in the next 
Number of The Veterinarian. 
