Exactly, no different to humans really, people generally don't find out about heart/ stroke and other health issues issues until their children are adults, so what are we to do, not have children?

Agree - as the owner of an epileptic dog whose lines DID have epilepsy, I would say, do not breed from any dog carrying genetic diseases.

But there are certain genetic conditions that can be tested for before people have children. Tay-Sachs as an example. My daughter and her first husband were both tested and she was found to be a carrier. He was not [neither was her second husband] therefore none of her children were born with Tay-Sachs but they could be carriers. And as such they and future partners will no doubt be tested before they have children.

There were no such tests before I was married or before I had children and as her father is long gone, when she found that she was a carrier she asked me to be tested, and yes, I am also a carrier although to the best of my knowledge neither of my sisters are.

Way back when these things were not known, Mother had various cousins who died within two to three years of birth, having been normal at birth but deteriorating until they were unable to do anything - even swallow. Looking back it is obvious that it came from Mother's side of the family, but both parents must be carriers for a child to be born with Tay-Sachs so there were other families also with carriers. But that is going back over 100 years now with no way of knowing.

Huntington disease can also be tested for before a person reproduces, and that can be inherited from one parent only. Therefore someone who has a parent who developed Huntington in later life can be tested before they decide to have children, and if found to be a carrier can take the risk of any children they have also developing the disease.

There are others as well but at gone 1am I do not feel like doing any research into the subject.

Yes lots of things can be tested for in both human and canine but not everything shows up until much later in life when you've already reproduced and maybe your offspring have too. The conversation wandered on to not breeding from dogs with cancer and that was what I responded to, seeing as cancer generally appears later in life when dogs have already been used for breeding how on earth would you avoid it.
Having just been diagnosed with something I've never heard of I'm well aware tests can be carried out to avoid passing it on to your children, bit late really as my children are grown men and one has a 9 year old daughter.

In humans, only about 10% of cancers are genetic/inherited. We all have cancer cells in us and it's only when our body isn't able to fend them off anymore (mainly due to poor nutrition, smoking, pollution, stress etc.) when the cancer cells develop out of control.
Assuming it's the same in dogs (though I've not got any studies to back that up), passing on cancer genes would be a minor concern. This would only be a problem with very specific cancers which can probably be tested for at an early age.

Realistically, what are the chances that a breeder knows exactly which and what to test for in their dogs? There are loads of things that a dog can be a carrier for. However if you already know that in the breed or that specific line there's a problem, I think you shouldn't breed.
My dog Wassily came from a litter of 3 Landseer puppies. The parents were FCI champions and all relevant health tests had been done. Wassily died from bone cancer at the age of 4 and one of his sisters died just a bit before him from the same thing.
Could be bad luck, or perhaps something in the breeding, we'll never know.
But I think if you know your dog is a carrier, you shouldn't breed from her because there are so many dogs out there that aren't and that would be more suitable for breeding. Just to breed from a dog because it's an 'excellent example of the breed' is selfish in my opinion. I find it much more important to breed for health, rather than standard.

That's true in many breeds but not all, so what is the alternative, keep a closed gene pool, because you are taking out a dog that will not pass on any inherent (tested for) problems if the breeding is done carefully.

A carrier should NEVER be bred to a carrier, but bred to a negative there is no possibility it will pass on the problem...if said breeders are ethical and know their pedigrees, then you will produce healthy pups and the gene pool will benefit.

And that's the issue we are dealing with, its OK for people to say, its poor breeding and you should not breed from dogs with cancer (that's bits obvious) but how on earth are you going to prevent something you 1) don't know will happen 2) have no way to test for .

If it can be tested for then we can do something, other wise as with us, we hope it does not happen.

That's it. You have to trust the breeder IS ethical and knows their stuff ... and the next breeder who wants to breed from one of the pups without seeing £££ in front of their eyes.

My dog was bred with the knowledge there was epilepsy in his lines. And relatives of his have been bred from too.