I already knew they both had murmurs - Oliver has been tested at the club show every year, and Aled was tested last year when I had only had him a few months. Oliver has stayed a grade 2, which isn't bad for nearly 9; Aled has gone from a 2 last year to a 3 this year, and he's only 3 years old in June - a bit more worrying, but no symptoms as yet, he has plenty of exercise and his weight is coming down, which is really all you can do. And no-one can predict whether he'll ever get any worse - it's very hit and miss. 2.5 years to 5 years seems to be the critical time - a serious murmur at that age is likely to cause problems later on, which is why the club's protocol recommends not mating dogs before 2.5. I presume early onset/late onset will be reflected in the EBV data, which is why Sarah Blott asks for heart certificates as well as scan results. After all, heart problems in older dogs are quite normal; it's the early onset which makes them so devastating n Cavaliers.
Looking at Saturday's statistics on the club website, it was a bit worrying that of the four 1-2 year olds with murmurs, three of them were Grade 5. My Blenheim Meg died of heart disease aged nearly 8 in 1993; all her litter brothers and sisters, and her mother, died of the same disease. Which is why I'm fanatical about getting my dogs checked - it's well worth entering the club show Not for Competition to get them seen by Simon Swift. They need to be KC registered to be shown, of course, but you can still enter rescue Cavaliers like Aled NFC if you spend £10 to get them on the KC's Activity Register - just pretend you're planning to do obedience or agility with them! It's a nice day out anyway.
Kate, Oliver and Aled