So so sad. I too , lost my beautiful Bobby to a kidney problem aged 8. He was from top breeders, tested for the usual, 6% coefficient, so might not be genetic. However, yours sound too much of a coincidence. Have looked up their inbreeding on the kennel club cocker health list? Do report your dog, and also tell the breeder. It’s fair to let them know because it’s better than rumours spreading.