A little background - When I adopted Yogi 2 years ago, I took him to the vet a couple days later. He was found to have a grade 2 heart murmur. We did xrays and nothing was determined. The Vet advised we can wait a year, do xrays again and see if there is any change. Well, I got Yogi with the intention of doing lots of stuff, and was really not comfortable with that plan, so we had an echo-cardiogram done by a cardiologist. There was no physical defect found with his heart and his murmur was determined to be physiologic. Fast forward to the last couple of months. Yogi developed a little bit of a cough. It was kind of a "is that a cough or is he hacking up grass?" kind of thing. Once in a while, not even every day and he seemed totally normal otherwise. No fatigue, no activity refusal beyond his usual lazy self, no labored breathing, nothing. Just this occasional hack. Well, the frequency of the coughing increased over a period of a few weeks and honestly it kind of snuck up on me until I watched a video back of he an Lillie playing. He actually stops play to cough about 5 times in a row. I thought holy crap, that's not right and so we went to the vet yesterday. The onset of his coughing may coincide with his bordatella vaccine, but I can't say that with certainty, although I will say it was about the same time. He coughs during physical exertion and immediately after drinking water. He had xrays yesterday and the vet said his lungs look "busy", meaning that you can see more white in the xray than she would like. She said if she were only to look at his xray she would expect him to be a much older dog. She is treating it as a vaccine induced case of bordatella and he is on a 7 day course of antibiotics. Since that is a best guess given the onset of symptoms and that he's not showing any other signs of illness, if that treatment doesn't work she will then treat as seasonal allergies and we will go from therr with a bronchial dilator and possibly a round of steroids. Ok, so there's that piece. What I'm mostly concerned about is that his heart is a little big bigger in the xray from yesterday than it was 2 years ago. Not a lot, just a little, but the bottom right side of the heart in the view taken from him laying down on his back is noticeably bigger, even to me. She is sending both sets of xrays to the cardiologist because she just isn't sure if it's cause for concern or not. So if she's not sure, I obviously am not sure... no signs at all of congestive heart failure, but I'm just uneasy with the whole thing. Nothing more to do but see what the cardiologist says and run the course of meds. I'm just not sure if the very small increase in the size of his heart is something to be concerned about?