Thanks so much everyone. We have been crying for 18 hours with a few breaks and our eyes hurt. In 2008, he had some pain and he cried out and everything and didn't want to move. It went away and 3 vets said it could be IVDD or spondylosis? After a year, it went away until this year (so free of symptoms for 2 years). He had episodes where he would stop and shake and be afraid to move and then it was like nothing happening. I was reading about hemangiosarcoma and it seems that there can be multiple bursts that drain and the dog is fine. Perhaps this one on his heart was the worst one in a series. I was reading about causes and they mentioned poison. When we lived in GA, he got really ill all of a sudden and the treated him for pancreatitis although he didn't have all the symptoms and they couldn't run all the labs to confirm it. They thought at first that he had bleeding in his colon--some hemmoraghic condition. Then they just thought it was pancreatitis but we never fed him anything out of the ordinary and he got better after a week. Now I wonder if he got into some poison or someone tossed him something. We lived in rural GA. Who knows. That was always a mystery b/c we never knew what it was. I wonder if there is a connection. It is weird how you just want to make sense of this stuff. We might try to foster a dog when we get through this b/c our elderbull Jade is lazy and Dozer was the only one who got her moving.