How would you feel?

[JenC]

Cancer happens. It's sad for the owner of the sire, but you can't really do much about it. As a breeder, you can't really do much about it. As the owner, I would raise the dog as healthy as possible and put the rest of it out of my mind.

[Meeps83]

I would freak out a little because nobody wants their pet to die, to die young, and especially to die young of cancer. However cancer is largely caused by environmental factors PLUS there will be much in the way of medical treatments and breakthroughs by the time the puppy the same age that his dad was when he died. The freak out would be short lived, and I would definitely express condolences to the breeder as these dogs, despite what they are bred for, are all pets and it must be heartbreaking for the breeder.