How serious is a level 1 or 2 heart murmur in a 3 month old boxer?

When I took my puppy to the vet the first time, she had no murmur, second time it was a stage 1, third time he tells me it's a 1 or a 2 and not to worry. I am a little worried. Will she be ok?

I would be worried if this was my dog, sounds like congenital heart disease which also sounds like it is progressing very quickly. Stage 2 is not incredibly bad but considering his age, this is bad.I'm sorry to say that your dog may not develop properly and is highly UNlikely to live a full life. Ask your vet about medication, food to support his heart ie with no cholesterole etc.Unfortunately the only real thing you can do is enjoy every moment you spend with him and make his life however short it is going to be an amazing experience for you both. If you got this dog from a breeder they also need to be notified as this is a genetic problem and the breeder should not be breeding these dogs.so sorry

I disagree with the first poster and agree with your vet. He probably just missed it the first time or else it opens and closes depending on activity level.A level one murmur is not serious. Many times they are "functional" meaning you don't always hear them. And many times a level1 murmur closes as the dog grows. Some humans have level 1 murmurs their whole life with no consequences at all. They are usually considered unimportant and functional. If it were a level4, you should be concerned. But not a a level 1-2. It isn't a health issue at that point.That said, the dog should not be bred. And the dog was not worth full price from a breeder. This is still a defect. But it is a very small defect, and your pet should live a normal life even without needing any medication.