It was a shock to find the first few reports of SARDS in Bichons
because this seemed to be a new malady for the breed. Upon
investigation it became clear that some of the instances of sudden
blindness that had been reported may have been SARDS instead of
cataract generated blindness or retinal detachment. While we see
only one or two reports a year of an affected Bichon, we do need to
make breeders and Bichon owners aware of the condition.
Unfortunately there is no treatment and it may or may not be
genetic.
SARDS stands for sudden acquired retinal degeneration syndrome.
There is little if any advance warning that the dog is afflicted
until the dog starts to run into objects, though in some instances
the progression may begin a week or two before total blindness
occurs. The pupils will appear normal but are not reactive to light
and are dilated. The condition is a sudden death of the cells (rods
and cones) that enable the eye to see. These same nerve cells are
the ones affected by PRA (progressive retinal atrophy) but these
appear to be distinct and different conditions.
Indications are that this is a disease of middle-aged and older dogs
and there are more reports in females. Onset may be related to
stress and there may be a connection to onset of Cushings but this
has not been proven to date. Increased thirst and hunger would
suggest there may be a relationship. Because the loss of vision with
SARDS is so acute, the dog often appears confused. Early ERG
examination (electroretinogram) shows no changes in the appearance
of the retina but the reading is “flat” indicating profound outer
retinal damage. The ERG remains unchanged over time. Hence the
diagnosis of SARDS is usually based on normal appearing ocular
fundus (the back portion of the interior of the eyeball, as seen
with an ophthalmoscope) with a “flat” ERG.
With early PRA some ERG recording is possible. The onset of the loss
in vision spans from a few days to a few weeks and involves both day
and night blindness. Early PRA primarily affects night vision first
and advanced PRA causes blindness. In SARDS, later ERG will make it
appear that the dog has PRA. Remember that PRA has gradual onset
while SARDS is virtually instantaneous. There do not seem to be the
same complications with SARDS as in PRA in that there is no uveitis
(inflammation of the iris and ciliary body of the eye) or
development of secondary cataracts. Diagnosis can only be made by a
veterinary ophthalmologist and an examination should be done as
quickly as possible to differentiate from PRA.
There is no treatment for the condition, which does not seem to be
painful for the dog, and the dog will not recover her vision. Her
distress results from the suddenness of the attack. In cataracts and
PRA, the loss of sight is gradual and the owner needs to understand
the confusion that the dog must feel to be instantly blind. With
other conditions, the dog has had a period of adjustment as vision
fades and she can adapt to the dimness and eventual loss of sight.
With SARDS, the pet needs help to overcome the disability and her
owner should be careful to keep her in familiar surroundings.
Initially the sense of smell and hearing seem to be diminished but
these other senses will sharpen with time and enable her to find her
way around.
It should be understood that other maladies may cause blindness and
can be treated. Some of these are optic neuritis (treated with
anti-inflammatory drugs); brain tumor or tumors pressing on the
optic nerve (treated with radiation); and possibly elevated blood
lipids associated with changes in blood pressure. Differential
diagnosis can be made by testing for those conditions. Nevertheless
the flat line ERG is the specific diagnostic result that will
confirm SARDS when these other tests have come back as negative.
Again we would stress the need for ERG to be done early rather than
later so as not to confuse the findings with PRA, a genetic
condition.
In response to several questions in regard to SARDS, we received the
following response from Dr. Kirk Gelatt: As to your questions,
SARD is not breed specific nor inherited. It is primarily in middle
aged female dogs. Bichon PRA is not as common as cataract; probably
by a factor of 1 PRA to 100 cataracts or more. SARD has been
associated with liver, pancreas, and adrenal gland abnormalities.
However, still no single association and often SARD dogs have normal
blood chemistries. End-stage SARD is difficult if not impossible to
distinguish from advanced PRA. While Dr. Gelatt’s answers
provide more questions to be asked, they do show that this condition
is not yet fully understood by veterinary ophthalmologists. Is there
a relationship to PRA? Is this a disease that will continue to
increase among Bichons? We hope that you will be alert to this
sudden cause of blindness and report any dogs that are diagnosed to
enable us to track it’s progress in our breed.
For more information on SARDS, see
http://www.sardsawareness.org/. This web site has a
hyperlink, titled Dealing with a Blind Dog, that may be helpful. To
assist the BFCA Health committee in understanding the implications
for Bichons, please report any Bichon diagnosed with the condition
to the Health Committee. We already know that there are many Bichons
with Cushings syndrome so it is likely that the numbers of SARDS
affected Bichons may increase if there is indeed a relationship.
Information for this article comes from the above mentioned web
site, an article in YOUR DOG, April 2004, Volume X, Number 4 and
various other texts. Additional information has been provided by Dr.
Kirk Gelatt, University of Florida, who is quite familiar with eye
diseases in Bichons. Our thanks to Dr. Gelatt for his continued
interest in our breed.
Important new information on treatment:
According to the following web site, there is the possibility of
restoring some vision to dogs afflicted with SARDS. You need to
read the report found at
http://www.caninecushings.net/forums/showthread.php?p=36766 for
more information. You may also want to print out the article there
for your veterinarian or veterinary ophthalmologist to read if they
have not mentioned the possibility of this treatment to you. While
we have learned of this new treatment, we make no guarantees that it
will be successful for you Bichon but you should have the
information in order to explore and find out more about it.
Please understand that it is important that you pursue this
immediately because delay may mean the treatment cannot succeed.
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