Like people, Dogs are subject to a large number of inherited eye diseases. Two which
can affect a Collie's eyes should be of concern to all breeders.
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COLLIE EYE ANOMALY

This is the most common of the Collie eye diseases, but it should be noted that Collies
share this disease with several other breeds. Researchers first noted this problem
nearly fifty years ago. It was later found to exist in most Collies and in most Collie
families. This so-called syndrome, meaning a group of conditions which appear in
conjunction with each other, is present prior to birth. Collie Eye Anomaly can be easily
checked when the puppies are 5-6 weeks old, by a qualified Board Certified
Ophthalmologist. It is something that your average Veterinarian is not qualified to
diagnose. The eyes must be dilated prior to the examination, so the interior of the eye
can be examined with an Ophthalmoloscope.

A dog is either given a “Normal” or "Affected" rating. If given "affected" the type of
abnormality is noted. It used to be popular to use a Grading System and still is being
used in certain parts of the country. Currently there is no universal, standardized
grading system.

Normal: A “Normal” eye rating is of course the best grading there is. (There are also
"Go Normals", which are so mildly affected at a young age, that later, the pale areas
disappear, leading to what is termed a "Go Normal". Keep in mind that these are still
in fact affected with CEA). There are variations even in "Normal" eyes. These
correspond somewhat to a dog's coat color. Thus it is often difficult to judge the
pigment in a Blue Merle's eyes as it is diluted along with his coat color.

Choroidal Hypoplasia, Chorioretinal Change:These refer to abnormalities in the
coloring or pigmentation of the choroid or central layer of the eye's lining. This is the
most common abnormality found in Collie eyes. Often referred to as mild CRC, Grade I
or Grade II, it is the least harmful and least severe form of CEA. Most dogs with this
eye grade function normally with no ill-effects or loss of vision.

Staphyloma, Coloboma, Ectasia: While not completely synonymous, these terms all
refer to a cupping or bulging in the eyeball usually in the area of the optic disc.

Vascular Disease, Tortuous Blood Vessels:Defects in the vessels of the eye which are
responsible for its blood supply or "nourishment." These may be malformed,
undersized, or even lacking.

Retinal Detachment: Loosening or separation of the inmost, or retina, layer from the
wall of the eye. This may involve a tiny area or the entire retina. It can be either one or
both eyes. The complete detachment of the retina results in blindness in that eye.

There is a new Genetic Test for Collie Eye Anomaly / Choroidal Hypoplasia. Please
visit the OPTIGEN website for details

Can the Collie's eyes become worse? Might he later go blind? The basic answer is
"No" as CEA is present prior to birth. However, a dog born with a severe Staphyloma
or with Vascular Disease may later suffer loss of sight if a detachment or severe
hemorrhage occurs. The majority of dogs that are slightly affected, will have perfectly
adequate eye vision throughout their life. (Even a dog with one blind eye will adapt
perfectly well in his surroundings.)

What have breeders done to improve Collie eyes? When the eye problem was
discovered more than 50 years ago, it was estimated that 90% of the Collie population
was afflicted with some form of eye disease. Because CEA has involved such a large
percentage of the breed, eradication has been slow . Over the years, with selective
breeding and eye checking of breeding stock, the numbers of affected Collies has
greatly reduced. ALL reputable breeders eye check not only their breeding stock, but
all puppies that are offered for sale.

How is CEA inherited? Most of the specialists agree that Choroidal Hypoplasia is
carried as a simple recessive. For a dog to show symptoms, both parents, even if they
show no signs themselves, must carry a gene for the condition. Evidence exists that
some other parts of the syndrome are inherited differently. Staphyloma, for instance,
rarely occurs except in the presence of Choroidal Hypoplasia. Dogs recommended for
breeding will vary according to the standard set by the individual doctor. The ideal, of
course, is to eliminate all but the clear, non-carriers, from the breed. Please note:
Even among the dogs that examine "normal", most are carriers of the gene. They
have a "hidden" or recessive gene for the condition and will transmit the gene to half
its offspring.

Two other conditions not part of the CEA, which can occur, should be noted:

Hypoplasia of the Optic Nerve: An undersized nerve which is noted where it enters
the eyeball. In extreme cases, this can cause blindness.

Corneal Dystrophy:This condition comes on when the dog is mature, often during
stress. Opaque spots appear centrally on the surface of the cornea. (It is often
confused by the layman with cataracts which occur in the lense.)

In the beginning there was a lack of veterinarians trained to examine eyes. Then in
1972, the American Veterinary Medical Association formed the American College of
Veterinary Ophthalmologists (ACVO), thus providing specialists in the animal eye
field. The Collie Club of America encourages its members to have all their puppies
checked as young as possible by a member of the ACVO. Where there is none in the
area, the alternative is to sell a dog contingent on a later check. No dog should be
used for breeding until examined and found to be above the examiner's standard.
Mount Airy Collies strives to produce NORMAL eyed pups
performing early opthalmologic checks and DNA testing on all
breeding stock.
www.optigen.com
Information copied from the Collie Health Foundation