Accepted Answer

Important Information…the advice I am providing is solely based on the information you are giving me. To accurately diagnose and treat a patient, a veterinary doctor-patient relationship is required. Before I can tell you what is wrong, I must see you pet and perform an examination. Over the internet, your description may be misleading and you may not see what a trained veterinarian would see. Therefore, the advice I give you is not to be taken as 100% accurate. I can tell you how I have treated cases in the past with similar symptoms and you must make a decision whether you want to follow my advice or not. This service is not a substitute for visiting your vet. With that in mind, let us start…

Hello wyly2
First let me commend you for considering to adopt this dog. Chances are he never had owners who cared for him. If you adopt him, you could have him treated depending upon how long the infection has been present. You might have a good chance to save him. However, to answer your question, the length of time he has left all depends upon the extent of the worm burden and how much damage has been done to the heart and vessels around it. It also depends on the breed. A ten year old large breed dog may only have an expectancy of 11 or 12 years. At first the disease causes coughing and exercise intolerance. Over time, weight loss, loss of appetite, labored breathing, and eventually, they might get bloated and fill up with water in the abdomen from heart failure and die. Obviously at the later stages, you wouldn't want the dog to suffer and would euthanize. But here is the trade off. some dogs are asymptomatic, that is they don't show much in the way of signs. This dog may live a "normal" good quality life until he dies of old age or some other illness. In other words, he may "out live" the disease If he is not suffering now, you might want to take him and give him a chance. Some people even believe at a certain age, treating them is not indicated for this reason.

Here is a link that may help explain in more detail. I must caution you that I have not reviewed this link and unless it is written by a veterinarian, the information can't be held to be medically accurate. But just to give you information that might help here it is:

http://www.peteducation.com/article.cfm?cls=2&cat=1621&articleid=743

Again, I am very happy to know people like you do such nice things for pets!
Best of Luck! Let me know how it turns out!