First off sorry,some advice for you second,if the vet starts in with medication to correct or hinder the affliction,get a script for it and have it filled at costco.My dad had a golden retriever that sported the enlarged heart,the vet gave the dog a month to live and as such dispensed the meds,the meds were super spendy,when she survived the month the vet wrote him a script and it was filled at costco for 1/3 the price at the vets.The med for the golden was the EXACT same med a human gets for an enlarged heart.My dads dog made it another 4 years on the meds,she was afflicted at about the same age as yours.