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What is Entropion?
Entropion is the inward rolling of
the eyelid, most commonly the lower lid. This irritates the
surface of the eye (the cornea) and may ultimately cause visual
impairment.
Entropion is a common hereditary
disorder in dogs. Selection for a particular conformation, of
exaggerated facial features with prominent eyes and/or heavy
facial folds, has created or worsened this problem in many breeds.
How is Entropion inherited?
It is likely that ectropion is
influenced by several genes (polygenic
inheritance) that affect the skin
and other structures that make up the eyelids, the way the skin
covers the face and head, and the conformation of the skull.
For many breeds and many
disorders, the studies to determine the mode of inheritance or the
frequency in the breed have not been carried out, or are
inconclusive. We have listed breeds for which there is a consensus
among those investigating in this field and among veterinary
practitioners, that the condition is significant in this breed.
What does
Entropion mean to your dog and you?
The problem is usually evident
before a year of age. Discomfort from entropion will cause
increased tearing and squinting. Your dog may be sensitive to
light and may rub at its eyes. Chronic irritation by the turned-in
eyelid may cause corneal ulceration and scarring which is painful
and, if not corrected, can impair vision.
Dogs who have had surgical
correction for a defect such as entropion may not be exhibited in
the show ring.
How is Entropion diagnosed?
The inrolling of the eyelid is
readily apparent. Generally both eyes are affected. Depending on
the degree of corneal irritation and the duration, there will be
other signs such as those mentioned above. Your veterinarian will
evaluate the degree of entropion and use flourescein dye to
determine if there is any corneal ulceration.
FOR THE VETERINARIAN: The
use of topical ophthalmic anaesthetic to anaesthetize the cornea
and conjunctiva will enable eliminatation of the spastic
component of the entropion in order to better evaluate the
anatomic component. This is important before surgery is
performed.
How is Entropion treated?
Entropion is corrected surgically.
If possible it is best to delay surgery until the dog is an adult
since the involved facial structures are still growing and
changing.
More than 1 operation may be
required. It is better to correct the entropion conservatively and
repeat the operation later if necessary, than to overcorrect
causing ectropion. In breeds such as the chow chow that have
particularly severe entropion related to heavy facial folds,
several surgeries may be required.
Breeding Advice?
Entropion is one of the eye
conditions that is a result of selection by breeders and a demand
by the public for such features as excessively prominent eyes and
heavy facial folds. A responsible breeding programme will choose
animals for breeding with a more normal head conformation, so as
to select away from these exaggerated facial features and the
problems associated with them.
The Vizsla Club of America has
recognized entropion as an unacceptable problem in their breed,
and advises breeders not to breed affected animals. Such
leadership by breed clubs is important in discouraging this and
other undesirable traits.
FOR MORE INFORMATION ABOUT
THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.
Where to find more information?
Slatter, D. 1993.
Textbook of Small Animal Surgery. p. 856-889. W.B. Saunders Co.
,Toronto.
Copyright © 1998 Canine
Inherited Disorders Database. All rights reserved.
Revised: December 19, 2008
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HELPFUL
LINKS ON ENTROPION
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