Heartworm disease is a serious and potentially fatal disease transmitted through the bite of an infected mosquito. The disease can cause lasting damage to the lungs, heart, and related blood vessels. Treatment can be costly and complicated, but illness is easily and effectively avoided by giving preventive medications.

Dogs and other canids, such as fox, wolves, and coyote, are considered the primary heartworm hosts, but these parasites can also affect other mammals, including cats and ferrets. There are treatments available for dogs, but prevention is the wisest approach to dealing with heartworms. In the early stages of the disease, many dogs may show few symptoms or no symptoms at all. The longer the infection persists, the more likely symptoms will develop. Clinical signs of infection include:

  • Persistent cough
  • Lethargy (tiredness)
  • Exercise intolerance
  • Loss of appetite and weight loss
  • Difficulty breathing and/or excessive panting
Early diagnosis is important; the earlier heartworm disease is detected, the better the chances for recovery. Apart from clinical signs, heartworm disease can be diagnosed using laboratory tests that check the pet’s blood for evidence of infection. It takes about 6 to 7 months for the infective larvae to mature into adult heartworms and can then be detectable through a blood sample. At Grayslake Animal Hospital, we use an Idexx 4DX snap test that checks not only for heartworm disease in dogs, but three other tick related diseases as well. In keeping with the American Heartworm Society guidelines, we require dogs aged 7 months and older to be tested for heartworm disease once a year.

Safe, easy to give, effective medications are available to prevent heartworm disease. Preventions are given monthly and are either topical (applied to the skin) or given as a pill or treat. Ask us which method and schedule of heartworm prevention are best for you and your pet.