I am so sorry to read this, especially after Seth's diagnosis. All the best for Thursday, for you and Caoimha.
What is so good about this forum, though, is that people are honest. Honest people who love their dogs and want the best for them, and aren't afraid to admit there may be problems in the breed. I have watched well known breeders (variety of breeds - not only cockers), in another country scrapping and arguing over genetic diseases, pretending they 'can't possibly be responsible'; blaming nutrition, over exercise, etc, and all the while the poor dogs are suffering as are their unsuspecting owners who tried to do everything the 'right way'.