Heartworm Disease in Cats

Heartworm Disease in Cats

By: Dr. Arnold Plotnick

Section: Veterinary Care In-depth

Therapy In-depth

The decision whether or not to treat feline heartworm disease is complicated, mostly because of the unpredictable nature of the disease and the risks of treatment side effects. There are no approved therapies.

  • Adulticide Therapy. Using drug therapy to kill the adult worms is a common way to treat heartworm disease in dogs, however it is risky and not routinely used in cats. The drug thiacetarsemide (Caparsolate®) given intravenously works effectively in dogs to kill adult heartworms. Caparsolate® has the potential to cause severe reactions in cats. Liver problems, kidney problems, pulmonary edema (fluid in the lungs) and a terrible skin reaction can occur if the drug leaks out of the vein during injection. The most worrisome side effect, however, is development of an embolus caused by a piece of dead worm traveling through the lungs and getting lodged.
    This causes sudden signs of respiratory distress that may be severe enough to cause death. Another drug, melarsomine (Immiticide®) is also used in dogs. Preliminary studies of Immiticide® on heartworm infected cats have yielded poor results and is not commonly recommended in cats. Melarsomine may also be toxic to cats in low doses. Adulticide therapy should probably be reserved for cats who have recurrent life threatening bouts of dyspnea as a result of their heartworm infection and are not responding to corticosteroid therapy. According to the American Heartworm Society, to date, there are no studies that indicate any form of medical adulticidal therapy increases the survival rate of cats harboring adult heartworms. There is no standardized agreed upon treatment for adulticidal heartworm therapy for cats.

    Please note that thiacetarsemide (Caparsolate®) is currently unavailable/off the market.


  • Corticosteroid Therapy. Intermittent therapy with corticosteroids (for example, prednisone) has been recommended in cats with evidence of lung disease resulting from the heartworms. Cats with no symptoms, or mild symptoms may be managed with intermittent corticosteroids as needed. The life span of a heartworm in a cat is approximately two years. If the cat can get through several recurrent bouts of coughing and respiratory difficulties on corticosteroid therapy for two years after the initial diagnosis, there is a good chance that all the worms have died and the cat may be fine thereafter.

  • Supportive Care. Cats with severe manifestations of heartworm disease may be treated in the hospital with oxygen, intravenous fluids, cage confinement, drugs to expand the airways (bronchodialators), drugs to improve heart function, and/or antibiotics.

  • Manual worm removal. Special surgical devices are sometimes used to manually snare and remove the worms. This is most commonly done when there is obstruction of blood flow affect the liver and heart.

  • No therapy. Cats that are stable may be monitored only. Monitoring may include chest radiographs every 6 to 12 months and given time for a natural cure.

    •  
    Printable Version
     
    Have a Pet Question?
    Review the Most Frequent Questions
    Answered by Dr. Jon and His Staff of Veterinarians
    Ask Dr. Jon
    Dr. Jon's Newsletter
    Yes! Send Me the Latest Health Information, Pet Tips, Pet Stories and more...
     
     

    Related Articles

    • 1 Heartworm Prevention Guidelines for Cats

      Heartworms are present in most parts of the United States and mosquitoes are the key – without them the disease cannot spread. Though most often affecting dogs, heartworm disease is rapidly becoming a...

      Read MoreRead More
    • 2 Congestive Heart Failure in Cats

      Heart failure is a condition, caused by an abnormality in the structure or the function of the heart, in which it is unable to pump normal quantities of blood to the tissues of the body.

      Read MoreRead More
    Related Articles
    • 1Heartworm Prevention Guidelines for Cats

      Heartworms are present in most parts of the United States and mosquitoes are the key – without them the disease cannot spread. Though most often affecting dogs, heartworm disease is rapidly becoming a...

      Read MoreRead More
    • 2Congestive Heart Failure in Cats

      Heart failure is a condition, caused by an abnormality in the structure or the function of the heart, in which it is unable to pump normal quantities of blood to the tissues of the body.

      Read MoreRead More
     

    Over 10,000 Veterinarian Approved Articles

    Dogs & Puppies
    Cats
    Related Articles
    • 1Heartworm Prevention Guidelines for Cats

      Heartworms are present in most parts of the United States and mosquitoes are the key – without them the disease cannot spread. Though most often affecting dogs, heartworm disease is rapidly becoming a...

      Read MoreRead More
    • 2Congestive Heart Failure in Cats

      Heart failure is a condition, caused by an abnormality in the structure or the function of the heart, in which it is unable to pump normal quantities of blood to the tissues of the body.

      Read MoreRead More