Heart mumurs are very common in Cavalier King Charles Spaniels - it was one of the 'breed' things (in the same way German Shepards often have hip problems etc).
My last Cavalier King Charles Spaniel had a heart mumur from a puppy - it was diagnosed at 12 weeks. At age 7 he had to go on to the tablets - this is young but because he had it from a puppy it did mean that he needed treatment sooner. It did end his life early unfortunatley but I think that is because he was born with it. He lived almost a year once he went on the tablets.
The cavalier that I have now will be 6 in March. He is very sickly and I usually put in about 3 insurance claims a year for his various problems! Up until this year his heart has always checked fine. This year it was picked up he has the beginnings of a mumur and I know eventually he will have to go on medication. The only good thing is, because he has gone this long without a problem, like yours, it should be several years before he needs the pills.
The symptom to look out for is coughing. When the condition starts to get bad, fluid can build up inside the lungs and the heart can start to enlarge. The dog will cough as a result - it was at this point that my first dog had to go on to the tablets. It is good that it has been picked up now as your vet can monitor it and make sure treatment starts at the right time.
Try not to worry - I know it is easier said then done - it will probably be years before your dog has any actual problems as a result of his mumur. Like I have said, it was 7 years before my first spaniel showed any clinical signs and the tablets helped loads when he went on them.
He is beautiful by the way.
Sabrina
xx
You are not the first person to say how handsome he is!
