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HOME TESTING for PRA

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By Leona Domino

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THE-NIGHT-BLINDNESS-TEST

  

The progress of PRA ( Progressive Retinal Atrophy ) begins with night blindness. The disease in Papillons is “ late

onset ” which means that visual diagnosis can be diagnosed after the ages of 3-4 years in older dogs by a Veterinary

Opthalmologist.  Meanwhile the dog has developed into an adult and perhaps has been used in a breeding program. 

 

Want a way to check on your dog’s night vision at home ?

There is a simple home test that can be used on puppies as well as mature dogs.  Dogs normally have very good night

vision ( far better than yours or mine ).  As PRA develops the first thing to be affected is difficulty navigating in

darkness.  This subtle indication is rarely noted by the owner as the dog is in familiar surroundings and manages 

very well.

 

However, if there is any question or you might have a "suspect" in your pedigree, you can do the home test easily.  

Veterinary Ophthalmologists often  do this test in their office as part of the screening process. This test can detect 

a problem long before the V.O. can visually see retinal changes at an older age.  

 

The needed equipment is minimal ...

 

1 One or two flashlights with good batteries. 
2 Red tissue paper covering the light from the flashlight. 
3

A totally dark room  ( you need a strange environment such your basement or a friends home )  

4 Obstacles to place throughout the room.
5 Friend to hold dog across the room from you.

  

Aim the red colored flashlights at the ceiling. Have a TOTALLY dark room.  Allow your eyes and the dogs eyes to 

“ night adapt ” to the darkness for a few minutes. You should be able to see with the red light.

 

Have a friend release the dog/puppy from across the room.  Call the dog to you.  The dog should be able to come 

to you directly and avoid all the obstacles.  If there is a slow, hesitant approach or the dog accidentally brushes 

or touches the objects in its path there is a definite problem with night vision. You need to seek further expert help.

 

Young puppies ( 12 to 16 weeks ) tend to be inquisitive and if normal-eyed will boldly walk up to the obstruction and

check it out before going around. They will also move about the room seemingly unaware of the lack of light.

Affected pups prefer to remain where you place them.
 
You must be sure that the dog being tested will respond in a positive manner , in other words the dog must know

and like the person calling it and know how to respond to the word or words used, such as "come". A familiar

person to the puppy will be able to call the puppy to her/him.
 
Also you may wonder if you are using the proper procedure but, after going through it several times you will gain

confidence. Do not take the dogs personality into consideration when you judge the results ... there is no room for

rationalization. Instead have the dogs with inadequate performances examined by an ophthalmologist and get

a "proper" ERG if possible.
 
The type of PRA found in Papillon puppies are born with poor undeveloped retinas . You will be able to use the above

test well in advance of the dog developing a retina that is observable to the V.O. ( ie: 2-3 years old ) .

 

It is a good practice to "screen" your puppies with the night blindness test before placing them.  Until there is 

a genetic test found for PRA, owners need to utilize what ever methods they have to check their dogs eyes yearly 

for development of problems.

 

The night blindness test is just a tool for breeders but does not replace veterinary ophthalmologist exams on 

a regular basis and certifying the test results with CERF.

 

 

Andi Meloon

( e-mail : andi2012@centurylink.net  )
Chair, Genetic Health Committee
Papillon Club of America