I was told my 4 month old Sphynx kitten was diagnosed with a level/grade 3 heart murmur. The vet suggested an ultrasound with a cardiologist, which I have scheduled. From others I've spoken to online and also from what I've read, heart murmurs can go away -- the kitten grows out of it. But my vet felt a level 3 murmur on a 4 month old kitten didn't seem like it was going to be grown out of. Obviously I'll do whatever for my kitten's health, but I was wondering if anyone else has had this experience. I don't want to postpone an important test, but the test isn't cheap -- at least $400 -- so I don't want to overreact either. Advice??