I think you are spot on with the extra panting. I definitely look back and noticed a kind of wheezing thing when he was running in the back yard. He also kneads a blanket like a cat. Now I think it’s a calming method he uses. Also looking back, he didn’t like to be touched when he was little. I remember saying- I wish he would just sit on my lap. The cardiologist told me to keep him living normally- no restrictions, because the heart is a muscle. I think if the dogs ever go into congestive heart failure, then the restrictions start. This diagnosis is so new, we haven’t gotten through the dog food that I have on hand, but the next bag will be low salt. He’s on Vetmedin, a Diuretic and a blood pressure pill. The cardiologist also said fish oil, but I haven’t ordered that yet. I am trying to get a date to neuter him. Sigh, I really would have liked 8 or 10 years without any medical problems…..