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RUNNY EYES (EPIPHORA)
IN THE CANINE
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THE PET HEALTH LIBRARY
Runny Eyes
(Epiphora)
EXCESSIVE
TEAR PRODUCTION IN DOGS AND CATS
Watery ocular discharge is a common concern of pet owners. Excessive tears
drain down the pet's face and, in time, the chronic exposure to moisture
produces skin irritation, infection, and odor. The fur becomes stained reddish
brown due to tear pigments, an especially non-cosmetic problem in white-furred
pets. The medical term for this condition is epiphora and it is one of the
most difficult conditions to resolve in all of veterinary ophthalmology.
There are two causes of Epiphora (excess tearing) in pets: irritation
to the eye and abnormal tear drainage.
IRRITATION TO THE EYE
One of the eye's natural responses to irritation is to produce more tears.
This helps flush away any irritants that might have contaminated the eye
surface. If excessive tearing is accompanied by squinting or pawing of the
eye, or if the excessive tearing should occur suddenly this should be taken
as an obvious sign of eye pain and veterinary attention should be sought at
once. Any accompanying loss of vision should be taken as an emergency.
It is the more chronic cases that are harder to manage. Eyes can certainly
become chronically irritated from viral conjunctivitis (probably the most
common reason for excessive tearing in cats), from glaucoma (painful increase
in eye pressure in the eye), or more commonly from eyelash abnormalities.
Some breeds of dogs naturally have hair in their eyes and this does not
cause irritation in most cases but in some cases it can. Hairs can grow
from the face onto the eye and cause irritation. Eyelashes can grow at abnormal
angles and rub on the eye. Eyelashes can even grow on the inner surface
of the eyelids and cause irritation. Often magnifying instruments are needed
to discover these tiny hairs and delicate surgical procedures are needed
to address them. Complicating the situation, however, is the fact that breeds
that tend to have eyelid and eyelash problems also tend to be the same as
those with faulty tear drainage anatomy (see below) which makes it very
hard to determine which of many possible causes is to blame.
Allergy, irritating dust or smog in the air, trauma, or infection can
lead to excessive tears from conjunctivitis. These problems can often be
treated medically by a general practitioner. For further reading we recommend
these links to other pages in The Pet Health Care Library:
NORMAL TEAR DRAINAGE
Once we are certain that a painful condition is not present, we can consider
that the drainage ducts of the eyes may not be normal. The normal eye is
most efficient at draining tears. Looking at the inner corner of the eyelids
(the side nearest the nose) one can see the pink, moist caruncle and
on the eyelid margins upper and lower openings called nasolacrimal puncta.
These are essentially drainage holes for tears. The puncta are the openings
to small passages called canaliculi which, in turn, open into a sac called
the lacrimal sac. The lacrimal sac drains into the nasolacrimal duct which
drains tears into the nasal passages and throat. (This is why we get runny
noses when we cry, why we sniffle when we cry, and why we can taste our tears
when we cry).
There are many problems that can occur along this drainage route. One
common problem, especially in the poodle and the bichon frise as well as
brachycephalic breeds, is simply that the eye socket is shallow. This means
that tears over flow from the corner of the eye because the eyelid space
there is not deep enough to contain them. These tears never make it to the
puncta and instead spill down the sides of the nose. This condition, if
present, cannot be repaired; it is simply the conformation of the dog's
face.
Alternatively, the eyelids may be turned inward (a condition called entropion)
blocking the puncta and preventing drainage. Another problem may be long
hair acting as a wick drawing tears from the eye to the skin. This hair may
be kept trimmed; though, if the hair is part of the nasal skin fold of a brachycephalic
breed, surgery may be needed to remove or alter the skin fold.
Old infections or injuries may scar the puncta, canaliculi, or nasolacrimal
ducts closed. Sometimes a vigorous flushing of saline through the ducts (performed
under general anesthesia) can re-open them. Sometimes the puncta are congenitally
closed (common in poodles and cocker spaniels) and can be surgically re-opened.
If surgery is required in these delicate little drainage structures, special
equipment is needed and a veterinary ophthalmologist is best consulted. For
help finding an ophthalmologist for your pet visit www.acvo.com.
ADDRESSING THE STAINING
An assortment of remedies have been suggested to resolve the unsightly
reddish stains that result from chronic tear drainage. Here are some comments
on suggestions that we have heard:
Adding a pinch of parsley flakes to the diet: we have no
idea if this works.
Low doses of tetracycline or metronidazole: variable success has
been reported but the problem is that this probably constitutes less than
responsible use of antibiotics and resistant bacterial strains may result
from this practice. It is generally frowned upon by pharmacologists.
Regular wiping of the area with hydrogen peroxide: this basically
serves to bleach the area and requires regular use to make a difference
Missing Link® Nutritional Supplements: the manufacturers list
reduction in tearing and tear staining as one of the benefits of their product
though they say 3 to 4 months of use are needed to see a change.
Copyright
1991 - 2007, Veterinary Information Network, Inc.
This work was originally published by Veterinary Information Network,
Inc. (VIN)
and is republished with VIN's permission.
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Q. My young dog seems to be in good health but with rather
watery eyes. Should I be worried or am I over-reacting.
A. Take a good look at your dog's eyes, preferably without
holding the dog still, so that the shape of the head is not altered by pulling
at the skin around the neck. Do the eyelids sit comfortably on the
cornea or does the dog screw her eyes up, causing the lids to curl in?
This is call entropion. Mild cases may ease as the dog grows,
although severe cases require surgery to prevent the cornea becoming ulcerated
and to relieve the pain. Do the lower lids fall forward, producing a
"shelf" for dirt to collect in? Once again surgery may help-but allow
time for the dog to finish growing, unless it is severe. If the lids
are ok, the cause may be eyelashes growing in the wrong place, or blocked
tear ducts. Either way, your vet will be able to give you the best advice.
The above information is simply informational.
It's intent is not to replace the advice of a veterinarian nor to assist
you in making a diagnosis of your pet. Please consult with your own veterinarian
for confirmation of any diagnosis. Your pets life may depend on it.