I bought a dog two years ago from the pound. Two days after I had Balto he was coughing when he would lay down so I took him to the vet thinking it was kennel cough. It turned out it was a heart murmur. They gave him medication for two weeks and a check-up prior to his neutering date. They said he was fine after they did a blood test to make sure it was safe to neutur him. My mother and I are starting to ride bikes again in marathons. I have always had someone ride with me or my dogs growing up. Would it be safe to have my dog train with me? I did a little test run this morning; took plenty of water and stops in shade. I just needed to know if this was okay or if this could possibly hurt my dog?