My dog failed his eyes this week, very upset by this. Just what are hereditary cataracts ? Both parents are clear, all four grandparents are clear. 3 litter mates tested so far are clear , I have great faith in the vet that done the test and issued the certificate. He  also breeds dogs.
What I have noticed on the form is that posterior polar sub-capsular cataracts are NOT hereditary in all breeds. So if dogs (different breeds) can mate with one another, DNA is almost the same, why are some breeds down as hereditary and some not? Sure all breeds should be hereditary. I know the breed club and AHT are looking into this form of cataracts . I also know I should of asked the vet about this at the time, but I was so upset and just didn't think to ask.
I hope you all can understand what I am trying to ask here, this young dog as proved himself in the ring and field work is coming along nicely, he also had a couple of future wives lined up, which now will not happen.

Both parents are clear, all four grandparents are clear. 3 litter mates tested so far are clear , I have great faith in the vet that done the test and issued the certificate.

Have they all (in particular grandparents) been tested every year up until at least the age of 7? Without that, results won't mean much. In our breed club the rules are you have to test until age 7. Also there seems to be 2 types -congenital hereditary cataract and non congenital, my breed is non congenital, could it be that yours is congenital? There's info in this leaflet:
http://www.bva.co.uk/public/documents/eye_leaflet.pdf

Not knowing what your breed is, I cannot offer much advice here , just a lot of sympathy. I have a lovely  gun dog boy whose father was tested affected with' HC' at the age of 7 and grandmother at age of 12, All previous testing had been fine. My boy's sire was only tested affected with' HC ' in one eye, the eye he had sustained an injury in while working . My understanding was that HC would affect both eyes. This result has always cast a shadow of doubt over my boy and his siblings. Flinti is now 8 and is tested annually . He remains unaffected.I will continue to test him every year. Happily he is DNA clear for both variants so far identified of PRA and is Gonioscopy Normal. I will continue to believe that his father 's and grandmother's results are dubious. As in humans, cataracts develop as part of the aging process. Until a DNA test is available ( unlikely due to number of genes involved) we will continue to have apparently random results as in the case of your boy.

> As in humans, cataracts develop as part of the aging process

Exactly right!

>> As in humans, cataracts develop as part of the aging process
> Exactly right!

Indeed - my oldie rescue girl is developing senile cataracts - a breed which is normally tested yearly for the early-onset form.  As she is around 12 years old and only developing them in the last 6 months, they are certainly due to old age.

On the other side of the coin, I read recently of a Siberian husky x Malamute (poupular BYB cross) aged only 1 year old with cataracts... very sad, and an indication of what can occur when testing isn't done.

That is so sad, in such a young dog.  :-(

> That is so sad, in such a young dog.  :-(

Aware we are going off-topic here - I wish I had the opportunity to quiz the owners a little - are they putting it down to bad luck, and are they genuinely unaware that tests exist to help prevent this? I'm sure they aren't the only ones, and I'm curious to know if, or where, any blame is being laid.

What I am asking is why this form of cataracts are hereditary in my breed but not all breeds? As I said parents, and grand parents on both sides have clear certificates, over quite a few years.i don't blame anyone, I have had dogs from this breeder for over 30 years and currently have 6 some which i bred my self,this is the first failure I have ever had.So how are tests meant to prevent this? By the way no other family members have been affected, with PPSC.
So please quiz me all you like!

The type of cataract your boy has been diagnosed with is, as far as I'm aware, considered hereditary in all the breeds in which it occurs.  It is almost always bilateral.I believe in certain breeds it is both hereditary and congenital meaning that it is present at birth and can be diagnosed in a young puppy. In other breeds the onset is much later and can be picked up at annual eye testing in adult dogs. What I am unclear about is at what age a cataract is considered age related /senile or as a diagnosis of HC. And indeed, is there a clear distinction between cataracts that are considered hereditary and those due to old age ?

In some of the breeds in which HC is a problem a DNA test has been developed. Even with the test there are problems involving the gene identified as causing HC in so far as not all dogs testing DNA Affected are developing cataracts and of those that do , there is considerable variation in the degree to which they are affected.