My four and a half year old lab has been found to have a heart murmur.   I am devastated and feel that we are now living on a knife edge and I am terrified that one day, suddenly, I may lose him..... having already lost a very young dog for different reasons.      I know that I am no different to any other but I would be devasted if I lost him, as he is my best friend.
We talk to each other, understand each other and love him to bits.

The vet on examination said that it was very dificult to confirm to start with and had to get a 2nd opinion but the second vet said the same and thought it was a Grade 2.    This is were my worry sets in.  I have researched it a little on the internet and whilst they say a Grade 2 is mild, they also say it depends on what is causing it I gather.  I then read about things like leaky valves and my head just snowballed.......as leaky valves seem to be very serious and progressive.
The fact that he is 4+  does this mean that he has progressed to this level at his age and it will continue to get worse?

I have agreed to have a Cardiologist  carry out a scan, which is due to be carried out shortly.
Also, I have since heard that a litter sister had also been diagnosed with a Grade 2 murmur but that vet didn't suggest any further action to be taken until problems manifested themselves.

Has anyone any experience in this? 

My friends Dobe bitch had a low level heart mummer all her life and lived the longest of all her dogs, to 14.

A poster on this site had a dog with a severe murmur in a breed prone to them, and he lived for 14 years albeit needing medication.

So wait and see what the specialist says.

Is your dog nice and lean, if not then ensuring he is might be a very good idea.

Hi yes, I don't have a weight problem.   he is very slim and a wee bit under-weight for his breed average  (i.e. a sensible weight).

I hope that Marianne comes on soon, and tells you about her boy, and how long he lived. 

Try not to panic, I'm sure that others will be along to reassure you soon.

I really would not worry about a grade 2. I wouldn't worry about a grade 3 either, and would only be slightly concerned about a 4.(As long as there was no breeding plans involved, of course! THEN even a grade 1 would matter, but only for the sake of not wanting to pass it on.) My Rufus, a Cavalier, had a grade 6 murmur so severe heart disease. He lived to 15 years, 2 months and 2 days -years above the average for the breed. :) He went from a grade zero to 6 in a matter of months. I also once had a Golden with a severely bad heart, the vet never told me a grade for his but I'd guess it certainly was a 5 at least, and he lived until 11. So please try not to worry. The one thing I'd do would be to ensure your dog never gets overweight, as extra weight is always a strain on the heart.

Like Marianne, I had a Golden Retriever with a severe murmer, (Was never told the grade, just that it was severe). I got her as a rescue at 6 months old and she lived till she was 17. I lost her to Cancer, nothing to do with her heart.

It depends on what kind of murmur.

AS Aortic Stenosis is the murmur most commonly seen in Boxers whereas MVD Mitral valve Disease is commonly linked to Cavaliers.

AS murmurs (caused by turbulant blood flow in the ascending Aorta leaving the heart) tend to be stable and often not worsening. I have a nearly 11 y old boxer diagnosed with a grade 1 at 12 months which has never worsened.

MVD is a faulty mitral valve between two chambers of the heart causing back flow and a growing inefficiency in blood flow aroung the circulatory system.
Ultrsound shows very clearly whether MVD is caused by one or more flaps of the valve and whether one or more chordae tendineae ( heart strings which open and close the valve) have broken.

Grade 2 is mild and without progression the dog adapts and may show no symptoms. No one can predict accurately how valve deterioration will pan out.

I know its easy to say, but Grade 2?!  You're not even at the stage where you need to think about worrying!  So please do stop worrying and enjoy how happy your dog is right now.  My dog has had a grade 5 murmur for just over 3 years now, she still has hour long off lead walks everyday and even undergone major emergency surgery since her diagnosis.  She is now over 10 and is showing no signs of stopping yet.  My vet is convinced she will out live him!

So yes, its not ideal for him, but its not a death sentence and wont slow him down.  Please pick yourself up and enjoy your dog!  Poor thing will be wondering why you are upset!