My dog went in for a checkup a year ago and had a highly irregular heartbeat and murmur. A trip to the cardiologist revealed an enlarged heart and the cardiologist suspected he was about to go into congestive heart failure. A year later the arryhthmia is detectable only after exertion and the murmur is barely detectable. I have been giving him Hawthorne and selected this tincture because of the level of the herb. I can't say for certain that the hawthorne is responsible but I do know that my dog's health has improved dramatically without resorting to prescription drugs.