I got an 18 mo old female Chihuahua from a breeder last week as a companion since my beloved Chihuahua died of old age earlier this year, and when I took her to the vet to make sure she was healthy, I was told she has a grade 6 heart murmur and likely only has months to live. The doctor took a chest x-ray and her heart is very enlarged and round. It's pushing her windpipe up. Right now, her lungs sound clear and she is not coughing. We have an appointment next week with a veterinary cardiologist, but I'm frantic with worry now. Is there any hope for a longer life or is this little puppy going to die before she's 2 years old? How long can medication prolong her life? How long might her life be without medication?