Signs of Heartworm Disease

A heartworm is a parasite found in nearly every country in the world. Dogs and cats become infected with this parasite through the bite of a mosquito carrying heartworm larvae. Its symptoms often go unnoticed at first, though without attention, the infestation will rapidly ravage a pet's heart and other vital organs, resulting in death.

  1. Cough

    • The first sign of a heartworm infestation in your pet is a cough. This is because heartworm larvae typically travel through the animal's blood stream and end up in the blood vessels of the lungs. The cough results from irritation caused by the enlargement of blood vessels and the presence of growing heartworm larvae.

    Exercise Intolerance

    • As the heartworm larvae develop into adults, your pet's ability to maintain energy levels will gradually decrease. This is because adult heartworms travel to the dog's heart where they ultimately damage blood vessels, thus compromising the heart's ability to pump blood. A dog or cat with this stage of infestation will show a very low tolerance for exercise, seem groggy and lethargic, and have a pronounced cough.

    Difficulty Breathing/Organ Damage

    • Adult heartworms will reproduce inside the animal's body, sometimes triggering an immune response. As your pet's immune system attacks new heartworm offspring, vital organs are often caught in the crossfire. As a result, breathing will become increasingly labored and you will notice wheezing and other abnormal lung sounds coming from your pet. At this stage of infection, he has already suffered severe damage to his lungs, liver, heart, and has fluid building up in his abdominal cavity.