Health Update - August 2011
Breeding Heartbreaks
As breeders we live in either a dream or a nightmare, breeding is such a wonderful hobby but as we all know it also has its heartbreaks. We do every test (of which thankfully for our breed there are now many) on our breeding stock and we can still come up with something new!
My last litter was born in March of this year and I watched as Mum produced 7 gorgeous healthy babies, then monitored them constantly for 2 + weeks, all growing and thriving well.
Ah, how lovely they are opening there eyes!! Good grief…. what is that I ask myself! Is it a Coloboma, not sure, don’t think so, but what am I seeing??
It was easy to see in the red tri with the lighter amber eye colour especially as one of his pupils was very obviously large and misshapen, but harder to pick up anything in those with dark brown eyes,
So for the next 3 weeks I tried not to panic too much, understatement! Then we were all off to the AHT for eye testing, “Please check them before the drops are put in”, I asked. “Why?”, was the response. “I think they have something unusual that I have never seen before!” was my reply.
Three hours later and after all the ophthalmologists that were available had come to look at this interesting litter and after hundreds of photographs and ultra sounds were taken, a diagnosis was given.
Half the litter was affected with ‘Iris Hypoplasia’, a few so mildly you would never see it with the naked eye.
Blank – so was I.
Of course I know more now, well nearly as much as the ophthalmologists it seems!
Iris Hypoplasia is quite rare and probably easily missed in the mildly affected, in fact after drops are used to dilate the pupil it would probably never be seen. It is a lack of development of the Iris (the coloured part of the eye). Imagine the iris like an onion made up of layers, if the top coloured layer doesn’t develop fully you would see a black odd shaped area as if part of the pupil, it has no effect on vision as only the top layer is missing. If the layers are underdeveloped all the way through you would have an Iris Coloboma which does let light through to the back of the eye and the dog will squint in sunlight to compensate.
I have asked all ophthalmologists I have met to date and none are aware of the heritability of the problem! As it is rarely seen little work has been done on the genetics. The AHT have been amazing, swabs were taken from the affected puppies, parents and grandparents where possible and these have been put on file for future study but 25 affected samples are needed to start DNA research.
So I am asking for you all to help. Have your dogs, especially litters, checked BEFORE drops are put in, this only needs to be done once. If you are in any doubt regarding the shape of your dog’s pupils the AHT are willing to check the possibility that you have this problem at no cost and will also store DNA samples (cheek swabs) for further research - just as they did years ago with the cataract research and eventually found the HSF4 mutation.
I am also going to get in touch with other countries to see if more samples can be obtained. Apparently a paper has been given in Europe on this problem where it has been seen in Aussies, so I can’t have had the only litter with it.
Thanking you in anticipation
Angie Challenger
KC Breed Health Coordinator