Rory- English Cockers are the 2nd best dog (of course Cavs are #1!). I grew up with several English Cockers and seriously thought of getting another before my husband surprised me with Spencer. The only downside is that most of the ones we had suffered from ear problems and all got heart disease, but none before 10 years.
I hope Rory's doing well. I saw your post about having surgery after Christmas. Please know that I think about you and he a lot and wish that everything goes well and that he's comfortable.
Insurance statistics in the UK and Ireland still show boxers and then westies as the number 1 and number 2 claiming breeds; cavaliers are third. I know many people with other breed dogs that have had quite serious, breed-related health problems -- cancer, severe hip dysplasia, awful skin conditions, and many cockers with the 'cascade of rage' problem making them unreliable for family homes. By contrast I see so many cavaliers over here, all the time -- many are fine older dogs 10 or older, never have had more than maybe some ear infections. Cavaliers have very few genetic problems compared to other breeds when you look at the lists but the problem is that two can be severe -- SM and MVD. My vet feels at least a cavalier with MVD can usually be successfully treated for years and have an excellent quality of life, whereas a Westie with a skin problem can be utterly miserable much of its life with conditions that often cannot be diagnosed or treated. Even with all the cavaliers my vets see -- they are in the top 10 of dog breeds in Ireland -- they only could think of three in their practices (three separate operations) that are showing any really noticeable potential SM problems. That's very few. But they see lots of boxers with very serious conditions.
Leo actually has moderate grade SM, but he is mildly affected at this time.
I don't think I'd find severe SM harder to deal with than I found, say, my cat Maisie's feline AIDS. She had bouts on and off with various maladies and rallied, lived with very poor teeth which in restrospect must have brought her much pain (cats are even better than dogs at hiding pain, my vets say) and finally she began to literally waste away. At that point, I let her go. She was probably not older than 4, and had had a tough life including a car accident. But she was a cheerful, self-contained little cat, and deserved a chance to live her life, short as it turned out to be.
But we all have our levels of what we can tolerate and what we can't. Having had Maisie, I know I would offer a hospice spot to a cavalier with known, serious SM, until the point came to let him or her go. I know others might find such a prospect unbearable.
I know that many people are able to handle a much higher level of heartache than I am. most of my vet school friends have several "special needs" animals at home and readily take in more when the opportunity comes along. many feel drawn to these "special needs" animals. I am the exception, in this group, in that I do not want to give my heart and home to an animal that will be chronically ill with problems and all the heartache that follows. I much prefer healthy animals. ;) Obviously this doesn't mean I'll turn away my Rory or any other animal that I own if it develops problems!! I'm committed to these animals for life and love them as my family! But I just can't knowingly invest my heart in another dog that seems almost guaranteed to have a problem.
My husband still says that if we could get a puppy and MRI it as a puppy to guarantee it wouldn't develop SM, he'd take it. And I think I'd agree. My parents have newfs and they always die of cancer, but the benefit outweighs the risk/cost because you usually have at least 10 years with the animal before it gets sick. So you know what to expect. With Cavs i feel like all I can expect is to freak out every time i see my dog scratch at its ears and assume it will develop SM and break my heart again. :(
I know there's always the chance your dog (of ANY breed, purebred or not!) will get sick and develop an unexpected horrible illness or get hit by a car or anything heartbreaking, but at least if that happens it's not like you intentionally got a dog that you knew would likely have this problem.....