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We
all value good health in our dogs – working and show ones. When we are
looking for a little new pup, we check that the parents have been hip
scored (and the scores
are not too high) and we also look out for if the parents have a current
eye certificate. Some dogs can suffer from
different eye diseases and until recently, you had to take your dog to
an eye clinic and have him checked by a
specialist vet in order to find out if the dog had any signs of any
known eye disease.
There are several different
eye diseases, like cataract, where it’s not quite
clear how these are passed on to the offspring, nor
how they affect the eye sight of
the dog. This is, however, not the case with the, perhaps, most feared
of all eye diseases anmongst retrievers: PRACD (progressive
rod-cone degeneration) which is a type of PRA (Progressive Retinal
Atrophy)
know to affect several different dog
breeds. This disease causes cells in the retina at the back of the eye
to degenerate and die, causing blindness in most affected dogs. It’s not
possible to tell when the dog will go blind – this could happen when it
is 4 years old or maybe later when it is 9 years old.
Apart from knowing how pracd-PRA effects
dogs, its also known that this disease is passed on from parents to pup.
Until now, it has not been possible to detect pracd-PRA, via an eye
clinic test before the dog started to be affected. Bearing in mind this
may happen late in the dog's life, the affected dog may already have
sired or had several litters of pups.
Optigen
Optigen is the name of an American company which have
recently managed to find and isolate the gene
that causes pracd-PRA in Labradors. This means
that even in pups, it
is now 100% possible to tell if the pup is likely to
suffer form pracd-PRA later on in life. The DNA test can be done either
from a blood sample or mouth swap from the dog and you’ll recieve the
result within 2-6 weeks.
The test will give you one of these three results:
“Normal/clear” – the dog doesn’t
have the gene and will never get pracd-PRA nor is
it not possible for the dog to pass on pracd-PRA to any of it’s
offspring.
“Carrier”
– the dog carries one pracd-PRA gene and will
never develop pracd-PRA but will be able to pass on the gene
to its offspring.
“Affected”
– the dog has pracd-PRA and is very likely to go blind. This also means
that the dogs offspring will be either ‘carrier’ or ‘affected’. A dog
needs to have the gene twice in order to be
‘affected’.
How Can We use this test?
If you ‘only’ want to use
your dog as a working dog, it doesn’t really matter if the dog/pup is
‘clear’ or ‘carrier’ as the dog will never get pracd-PRA. Should you,
however, wish to breed your bitch or dog, the test could serve as an
important tool on your choice of bitch or stud dog.
If you breed two ‘clear’ dogs it will be possible to
guarantee that all the pups in the litter will have a ‘clear’ status.
If you breed two dogs, one is a ‘carrier’ and one is ‘clear’, you should
in theory end up with a litter which will have 50% ‘clear’ pups and 50%
‘carriers’. Should someone wish to breed from some of the pups, it
would be a very good idea to optigen test the litter or at least the
pups which the owners wish to breed from. As mentioned earlier on, a
dog needs to have the gene twice in order to
develop pracd-PRA and this risk is significant should you breed two
‘carriers’ as both the mother and father could pass on the gen.
Should you breed an ‘affected’ dog, all offspring will,
as a minimum, be carriers even if it’s bred to a ‘clear’ dog.
Don’t Panic!
The near future will bring on a transaction period
amongst labradors and specificly labradors of working lines. The test is
still fairly new and as people are starting to have their dogs tested
some very well known stud dogs are now found to be ‘carriers’. These
are all excellent working and/or trial dogs and their names are found in
many pedigrees. They have all tributed to the working labrador breed by
producing some of the best working and trialling labradors in both the
UK as well as abroad. Without them, the UK would probably not have some
of the best working labradors in the world.
If we were to remove every single ‘carrier’ working
labrador in the UK tomorrow, the labrador breed would collapse.
It is possible to breed from a ‘carrier’ dog/bitch and and some very
experienced dog breeders may even consider to breed an ‘affected’ dog,
in order to preserve a specific bloodline, but if we wish to strenght
the eye health of the labrador the goal must be to try and breed out all
‘affected’ dogs.
Good luck with your dog’s test! |
