Heartworm Awareness Month

The month of April is Heartworm Awareness month! According the the American Heartworm Society estimates that over 1 million pets in the US have heartworm, a completely preventable disease. 

No state is heartworm free. We at Georgia Veterinary Associates recommend year round heartworm and parasite prevention because it never truly get cold enough, for long enough to kill mosquitoes or other parasites. 

What is Heartworm?

According to the American Veterinary Medical Association "Heartworm is a preventable, but serious and potentially fatal, parasite that primarily infects dogs, cats and ferrets..." Heartworm infection in pets occurs all over the world, particularly in areas where mosquitos are prevalent. In the United States, this disease was once limited to the South and Southeast regions; however, it is now found in most areas around the U.S. While Heartworm is treatable, it is much easier, safer, and cost effective to prevent the disease. 

What causes Heartworm?

Heartworm disease is caused by a blood-borne parasite, Dirofilaria immitis. This parasite is transmitted by mosquitoes and can cause life-threatening illness. Adult heartworms live in the right side of the heart and the pulmonary artery. They can cause physical damage to the heart, significant inflammation in the lungs, and can cause damage to other organs such as the kidneys. Female adult heartworms can be between 6 to 14 inches long and can live up to 5 years.

But how do they get into the heart? When an infected mosquito bites a dog or cat, it deposits heartworm larvae into the body. The larvae migrate for several months before arriving in the heart or pulmonary arteries. Once the larvae mature, they begin to release immature heartworms, known as microfilaria. Microfilaria live in the pet’s blood for about one month and may, in turn, be ingested by mosquitos feeding on the pet.

How do Heartworms affect my dog?

Adult heartworms live in the right side of the heart and the pulmonary artery. They can clog the heart and pulmonary artery, reducing blood flow to the kidneys, lungs, and other vital organs. They can cause damage to the valves within the heart, decreasing the heart’s ability to function and ultimately leading to heart failure. The body’s inflammatory response to the worms can also create significant inflammation within the lungs, leading to coughing, shortness of breath, and in severe cases pulmonary embolism. Dogs with early stages of heartworm disease often show no symptoms, which is why annual testing is so important. Dogs with more advanced disease or heavier worm burdens may have a soft, dry cough. They may also be less active, pant even at rest, or be weak. Your veterinarian may detect a heart murmur. Severe cases may develop heart failure, and owners may notice a distended abdomen caused by fluid accumulation or even sudden collapse.

How do you test for Heartworm Disease?

All dogs should be tested annually for heartworm disease, even dogs who regularly take heartworm prevention. The heartworm test is typically performed during a routine wellness screen and takes just a few drops of blood. This test detects the presence of adult worms, which take 5 to 6 months to develop after initial infection, so it is not performed in puppies under 6 months of age. If an initial screening test is positive for heartworms, your veterinarian will recommend additional follow up testing. This may include checking blood for microfilaria (baby heartworms visible under a microscope) or sending out other tests to confirm the positive result.

How do you prevent Heartworm Disease?

There are two main ways to prevent Heartworm Disease. First is a monthly, flavored chewable that kills and larvae that may have been injected into your pet. Second, there is an injectable shot that last 6-12 months depending on what one you'd like. We at Georgia Veterinary Associates recommend Sentinel Spectrum for Heartworm prevention. We also recommend Sentinel Spectrum because they are almost always running some sort of instant rebate, which means savings for you and protection for your pet! 

Most Heartworm prevention companies also have a guarantee. If your pet has had yearly, negative heartworm tests, and have been on year round preventions, they will pay for treatment*. 


Learn more about the deadly disease from our very own Dr. Stephens in the video below:

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