What Causes Cough With Heartworms in Dogs?

Dogs cough for a variety of reasons. They may be allergic to pollen, they may get kennel cough from an animal shelter or boarding at the vet, they may have infected teeth or the worst case---they may have heartworm. Because coughing is symptomatic of all these illnesses, heartworm is difficult for you to detect as a pet owner. So, particularly if you do not give your dog a heartworm preventive medication, consult your vet if he coughs for more than five days, says the Pet Education website.

  1. Lung Damage

    • Coughing is the most obvious symptom of heartworm, according to the Dog Heartworm Guide website. When a mosquito bites a dog that's already infected with heartworm, it ingests heartworm larvae, according to the 2nd Chance website. If that mosquito then bites your dog, the heartworm larva passes though your dog's body and rests on the right side of the heart. Over time, these larvae enlarge the heart and multiply in your dog's lungs. The enlarged heart also presses against the dog's windpipe.

    Coughing Sound

    • According to the 2nd chance website, coughing as a result of heartworm will range from dry to moderately moist. The Pet Education site adds that labored breathing may accompany the cough, which is a "non-productive" cough, meaning you dog won't cough up fluid or blood. The cough is usually worse when the dog is lying down.

    Physical Signs

    • A heartworm-infested dog is unable to exercise even mildly without coughing and wheezing, according to the Dog Owner's Guide website. He may even cough on your daily walks together. The 2nd chance website also says that infected dogs look tired and worn, often prematurely gray around their muzzles and toes, sporting a dry and musty coat and noticeable thinness along their backs. As the disease progresses, the dog will appear chubby due to an enlarged liver and an excess of fluid in the stomach.

    Treatment

    • Treatment for heartworm is rough and unpleasant---arsenic injections that kill the heartworm parasites that are causing the heart and lung damage, according to 2nd Chance. The vet will usually give three shots (one shot during the first visit and two shots given 24 hours apart the following month), unless the dog is too weak for the treatment. In severe cases of heartworm, the vet may only give one shot and then prescribe monthly heartworm preventative.