My mother took a kitten (about 1 year old) I adopted recently to the vet today because I was at work. When she got home she told me the vet said he has a heart murmur. I'll call the vet as soon as I can get in touch with him to get the details but this has made me extremely upset because I love my kitten very much. How serious is this? I was told it was a level 2. I have no idea what any of it means, can someone help me out with some information until I can talk in depth with the vet?