G. J. COLLINS. 
52 
toms are pain and photophobia. Lacrymation and blepharo¬ 
spasm is what usually attracts the attention of the owner or at¬ 
tendant, and the animal is brought to the veterinarian for inspec¬ 
tion and treatment. Constant closure of the eyelids, associated 
with partial opacity of cornea and myosis, is strongly indicative 
of acute corneal ulceration, provided there is no evidence of a 
corneal puncture, with infection of cornea or aqueous humor. 
The ulcer begins with a grayish or grayish-yellow infiltra¬ 
tion of a circumscribed portion of the cornea. This is later ac¬ 
companied by suppuration, and the superficial layers are cast off, 
and this is the beginning of the ulcer. Pathologists call it a 
molecular disintegration; anyhow, it is a loss of substance. Some¬ 
times the ulceration is rapid and other times the process is pro¬ 
longed (chronic). It may extend in area or depth, or both. May 
advance in one direction, or in two or three directions, or all 
around the circumference. Sometimes heals on one side and 
advances on the other (serpiginous ulcer). There is almost in¬ 
variably a more or less grayish infiltration of the cornea imme¬ 
diately surrounding the ulcer, with constant ciliary injection. 
If the ulcer is superficial, the diseased or destroyed portion 
will be cast off in a few days, the infiltrated border will com¬ 
mence to clear, and repair set in. This is accompanied by the 
appearance of capillaries or blood vessels, which arise or come 
from the limbus. 
The ulcerative process terminates in cicatrization. If there 
is difficulty in the determination of an ulcer or ulcers, instill a 
few drops of a two per cent, solution of fluorescein, which stains 
the ulcer or ulcers and infiltrated area green. 
Deep ulcers have more pronounced symptoms and the com¬ 
plications and sequela more serious. There may be, and there 
usually is, more or less conjunctivitis, iritis and hypopyon. 
Hypopyon is a collection of pus in anterior chamber, usually 
seen at bottom of anterior chamber, and is not derived from 
ulcer, but is an exudation derived from the iritis or iridocy¬ 
clitis; in other words, a coagulated exudate. It may partially or 
completely fill the anterior chamber and remain fluid or semi- 
