My bichon/poodle is 12 years old. He has an enlarged heart that he has had for a couple of years. He's just been getting slower and coughing some. I give him meds for cough only when needed. Vet's been watching it and it's not bad enough for any other meds. Just recently I took him in to vet because he seemed out of sorts, breathing harder and barking out, like in pain. She did xray to compare last xray to see if heart was larger or fluid in lungs, etc. She said there was no change. Sent out to radiologist, they said same. She drew blood and blood came back okay...so nothing there. She put him on antibiotics because his teeth are bad, in case there may be some underlying tooth/gum problem. There is still something else going on. He is tense and rigid, he lays only on his left side and curls his right paw under. Occasionally he will bark or wince as in pain. He gets up walks around and is eating but as he is sleeping right now, he appears to be breathing okay but is shaking on exhale. My last vet bill was over $400.00. What are we missing? Help, thanks. Donda