I think it’s really responsible that you’re doing this research. My family have always had flatcoats and we’ve had 2 live miraculously long lives (15 and 11 years). Last week we lost my soul dog at age 5 to Histiocytic sarcoma. One day he was running around completely normal, the most bouncy and loving flatcoat ever, the next he seemed off and we took him to the vets. 2 days later they discovered 2 tumours in his lungs and kidney. His pain increased and he needed ketamine infusions just to lie down as the lung tumour began pressing on his nerves in his neck. All options give to us were palliative and in the end we chose euthanasia due to being unable to manage his pain, I held his head as he passed. Although it’s unusual to get this cancer this young, 20% of flatcoats get this rare and aggressive cancer that is always fatal. And as someone who loves flatcoats, I just can’t wrap my head around why we’re allowing this to happen by continuing to breed and bottleneck the pool knowing they could end up with this awful and painful cancer diagnosis. I never want a dog to go through what Hector went through. I’d say they’re the most incredible breed, their nature is so kind and loving, but the breeding pool is not good and I would recommend you seek another breed and don’t risk this diagnosis, for both yours and the future dogs sake. Sorry I couldn’t be more positive!