Even if you don't give heartworm preventitve I hope everyone is at least getting a heartworm test done at your bullies annual exam. Most of the time it's not caught until it's too late unless you test for it. "Initially, there are no symptoms. But as more and more worms crowd the heart and lungs, most dogs will develop a cough." A friend of mine adopted a 5 year old male American Eskimo dog from the ASPCA. Wonderful dog, he was so nice, laid back, an awesome dog. My friend fell instantly in love with him. He didn't appear to have anything wrong with him. A couple weeks after she adopted him she took him to get his shots. Well the vet she took him to he had actually been to before with his previous owners. At like a year old he had tested positive for heartworm on a visit with his previous owners. They never treated it. Here he was 4 years later and the heartworm had become so advanced he had to be put down. My friend had only had him for a couple weeks but had already totally fallen in love with him, she was devastated. And of course really mad that someone neglected him so badly