Heartworm disease is a serious threat to dogs, caused by the parasite Dirofilaria immitis. It begins when an infected mosquito transmits larval heartworms to your dog. These larvae develop into adult heartworms that settle in the bloodstream, lungs, and heart, and can grow up to a foot in length—posing a significant health risk or even causing death. Fortunately, heartworm disease in dogs is easily preventable.
How can you tell if your dog is showing signs of heartworm disease?
It’s nearly impossible to prevent mosquitoes from biting, which is why you should have your dog tested annually and keep them current on a heartworm preventative. These treatments work by eliminating heartworm larvae before they mature and inflict serious damage.
In the early stages, heartworm disease often shows no symptoms at all. However, as the infection progresses, symptoms become more apparent—especially in active dogs, those with other health issues, or pets with a heavy heartworm burden.
Common signs of heartworm disease in dogs include:
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A mild, persistent cough
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Reluctance to exercise
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Fatigue following moderate activity
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Reduced appetite
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Weight loss
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Difficulty breathing
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A swollen, fluid-filled abdomen
If you notice any of these symptoms, it’s crucial to take your dog to the veterinarian promptly. Early diagnosis significantly improves the chances of a successful outcome.
In cases where dogs are heavily infected, a sudden blockage of blood flow in the heart can occur. This may manifest as rapid, labored breathing, dark or coffee-colored urine, and pale gums. Without urgent treatment, the survival rate drops dramatically.
Diagnosis typically begins with a simple blood test. If heartworm disease is confirmed, further evaluations such as x-rays may be necessary.
Prevention vs. Treatment of Heartworm Disease in Dogs
While there are safe and effective treatments available, treating heartworm disease is expensive, complex, and can sometimes lead to complications. Moreover, damage caused by adult heartworms can persist even after successful treatment. For these reasons, prevention remains the best strategy.
