Progressive Retinal Atrophy (PRA)

During the last few years there has been an eye disease discovered in many breeds.  It is nothing new, the first case of PRA was observed in England almost a hundred years ago.  We have tried to believe it could not affect our lovely Lhasa Apsos.  To be realistic, though, why could it not happen to our breed when all other Tibetan breeds are affected with PRA?

Progressie Retinal Atrophy (PRA) is the medical name of the disease.  It means that the thin light sensing layer, the retina, in the back of the eye slowly will die out.  The dog has full sight at birth and then slowly begins to lose cells of the retina.  The unfortunate thing about PRA is that it may not show up until the dog is around two and a half to eight years of age.  It will always end up in blindness.

The first signs can be seen when the dog doesn’t want to go out at night or when the dog is afraid of going into a dark room.  The dog has lost the night vision.  When PRA progresses the dog can go upstairs but seldom downstairs, it will jump up on the sofa or the bed and must be helped down.  When it has come this far it is important not to move any objects in the dog’s surroundings.  The dog can still perceive moving objects but will not see stationary things.

You can often see a green or orange shine reflecting out of the dog’s eyes.  This is due to incoming light reflecting off the retina.  Normally we don’t see this except in very dim light, because in most situations the pupil is constricted.  In PRA, the pupil will often be widely dilated – the eye’s vain attempt to let in more light.  Some dogs can be aggressive when loosing sight but most of them will still be sociable.  Even if your Lhasa Apso has gone blind it can live a normal life if you don’t move the dog from it’s normal surroundings.  When loosing one sense the remaining senses will be developed and more used. 

The disease doesn’t follow what we call common sense because the dogs develop their other senses to a level we can never imagine and we are completely fooled into thinking a PRA dog still has very good sight.

An eye specialist veterinarian can see if there is any PRA in the eyes of your Lhasa Apso.  Only dogs having PRA will test positive.  They have got a defective gene from BOTH their parents.  If your dog is tested unaffected from the disease it can still be a carrier of the defective gene and this gene has come from ONE of the parents.

If you plan to breed, it is necessary to test the stud dog every year and the bitch each time before breeding them.  The only thing we can do to date is to examine our Lhasa Apsos and not to use proven carriers of PRA in our breeding.  In future we hope there will be a gene test available where we can identify the carriers.  While we are waiting for this method, every Lhasa Apso breeder and owner should examine for PRA and report the test results to their local Lhasa Apso Club and of course to the breeder of the tested dog.  Breeders all over the world are working together to accumulate information about PRA, because they need to know the dimensions of the PRA problem in their respective breeding populations, and we need to encourage the research toward a DNA test for the disease.