Miette

My approx 3yr old severely cross bred dog (staffy, kelpie, cattle dog and other unidentified breeds) was diagnosed with a level 1 heart murmur today during a rountene check up. She is desexed, 12.9 kg, small build and healthy. I rescued her from an animal refuge 2 years ago so I have no idea of her history. I was just hoping that someone could tell me a little bit more about the diagnosis & what I can do to help her in anyway.