There are a number of conditions that cause a watery or mucus-like discharge
to overflow the eyelids and run down the sides of the face, staining the hair.
do not cry as people do, so this is not a factor to be considered as one of the
causes. In all cats with a runny eye, the cause should be determined so that
proper treatment can be given.
First, it is important to determine whether the eye is red or irritated.
Irritating eye disorders are characterized by excessive tearing along with a
red or painful eye. However, if the eye is not red, then a blockage in the tear
drainage system is the problem.
Keep in mind that excessive tearing or a sticky, puslike discharge from the
eyes or nose is frequently associated with feline viral respiratory infections.
This possibility should be investigated before the eye alone is treated.
In cats with this condition, the discharge is due to an overflow of tears
caused by a blockage in the tear draining system. Inadequate tear drainage
should be considered if the cat has a persistent eye discharge without
A cat may be born with an inadequate tear drainage system. However, in most
cases, nasolacrimal occlusion is the result of scarring from eyelid injuries
acquired in cat fights. Other causes are chronic infection in the duct system
and plugging of the ducts by thick secretions, dirt, or grass seeds.
To see if the drainage system is open, a veterinarian stains the pool of
tears near the inner corner of the eye with fluorescein dye. If the dye does
not appear at the nostril, the tear duct is blocked on that side. Nasolacrimal
probes are inserted into the duct opening, and various flushing techniques are
used to show the point of obstruction. The flushing often removes the blockage
and opens the duct.
An overflow of tears, accompanied by unsightly staining of the hair below
the eyes, occurs in some cats with short noses, large, prominent eyes, and flat
faces. The problem is seen most often in Persians and Himalayans, and other
breeds with shortened muzzles. These breeds are subject to chronic eye
irritations and infections that produce tearing. Their facial structure usually
causes a narrowing of the nasolacrimal duct and a shallow tear lake at the
inner corner of the eye. All these factors may contribute to the problem.
Treatment: If there is no correctable cause, symptoms can often be improved
by administering a broad-spectrum antibiotic. If the cause is a chronic
infection, the antibiotic will treat it. Tetracycline is the drug of choice. It
is secreted in tears and also binds that part of the tears that stains the fur.
If improvement is only due to the binding action of the drug, the face remains
wet but not discolored. Tetracycline is given by mouth for three weeks. If the
stain returns after treatment, then long-term administration might be
considered. Some cat owners prefer to add low-dose tetracycline to the cat’s
food for long-term control. Tetracycline should not be given to growing kittens
or pregnant queens, as it will cause problems with the development of teeth and
When cosmetic considerations are important, you can improve your cat’s
appearance by clipping the hair close to his face.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"