Heartworm disease is a serious and potentially fatal condition affecting dogs across the United States, including Georgia. The disease is caused by Dirofilaria immitis, parasitic worms transmitted to dogs through the bite of an infected mosquito. As heartworm disease is prevalent in areas with warm, humid climates — like Georgia — it’s critical for dog owners to be aware of the risk factors, the disease process, available prevention strategies, and treatment options to safeguard their pets.

Georgia’s subtropical climate is an ideal environment for mosquitoes, which are the primary vectors for heartworm transmission. Our state's warm weather, combined with seasonal rainfall, creates an environment where mosquitoes thrive year-round. While the risk of heartworm disease is highest during the warmer months, it can occur any time of the year due to the persistent mosquito population.

Key Risk Factors:

1. Geographical Location: Dogs living in urban and rural areas of Georgia are both at risk. However, areas with standing water, such as ponds, marshes, and even backyard pools, have a higher concentration of mosquitoes.

2. Mosquito Activity: Since heartworms are transmitted through mosquito bites, any dog that is exposed to mosquitoes is at risk. Even indoor dogs are at risk if mosquitoes manage to enter the home.

3. Lack of Preventive Care: Dogs that are not on a year-round heartworm prevention regimen are at a significantly higher risk of contracting the disease.

4. Age and Health: While any dog can contract heartworm disease, younger dogs may not show symptoms as soon as older dogs. Additionally, dogs with weakened immune systems or those with other health problems may be more susceptible to severe cases of heartworm disease.

Heartworm Disease

Heartworm disease occurs when a dog is bitten by a mosquito carrying heartworm larvae, known as microfilariae. The larvae enter the dog's bloodstream and mature into adult worms over several months, with the adult worms residing primarily in the heart, lungs, and blood vessels. Here's how the disease progresses:

1. Infection: After an infected mosquito bites a dog, the larvae are deposited into the bloodstream. These larvae travel through the blood vessels and take about six months to mature into adult heartworms.

2. Adult Heartworms: Once matured, adult heartworms can grow up to 12 inches long. They live in the dog’s heart and lungs, causing inflammation, damage to blood vessels, and impaired organ function. In severe cases, heartworms can obstruct blood flow and lead to heart failure.

3. Microfilariae Release: Adult heartworms reproduce, releasing their offspring (microfilariae) into the dog’s bloodstream. These microfilariae can then be picked up by mosquitoes during subsequent bites, continuing the cycle of transmission.

4. Symptoms: Symptoms of heartworm disease vary depending on the severity of the infection. Early signs include coughing, fatigue, and reduced exercise tolerance. In advanced cases, dogs may experience difficulty breathing, weight loss, and fluid accumulation in the abdomen. Severe infections can lead to heart failure, organ damage, and death.

Prevention of Heartworm Disease

Prevention is the most effective way to protect dogs from heartworm disease. Thankfully, there are several preventive measures available that can significantly reduce the risk of infection.

1. Monthly Heartworm Preventives: Oral medications or topical treatments, such as Heartgard or Interceptor, are widely recommended. We also have a injectable product called ProHeart that can be given once a year by your veterinarian to prevent heartworm disease. These medications kill the larvae before they can mature into adult heartworms. Consistent administration is essential, and it’s important to continue prevention throughout the year, even during the winter months, as mosquitoes can still be active in Georgia.

2. Annual Heartworm Testing: Even if a dog is on heartworm prevention, it’s essential to have an annual heartworm test. This helps detect any potential infections early, as heartworm disease can develop even in dogs on preventive treatment if the medication is not administered correctly.

3. Environmental Control: While heartworm prevention pills and treatments are the most effective measure, controlling mosquitoes around the home can also reduce the risk. Remove standing water from yards and use mosquito repellents designed for pets and outdoor spaces.

If a dog is diagnosed with heartworm disease, treatment is possible but can be costly, challenging, and carries some risk due to the nature of the disease. The treatment is generally more effective when started early, before the heartworms cause irreversible damage.

Treatment Options:

1. Initial Stabilization: Before undergoing treatment, the dog may need stabilization, especially if the infection is severe. This could involve managing symptoms such as coughing, fluid accumulation, and inflammation in the lungs.

2. Adulticide Therapy: The primary treatment for heartworm disease in dogs is an injection of an adulticide (typically melarsomine) to kill the adult heartworms. The treatment consists of multiple injections over several weeks. This therapy is not without risk; killing the worms can cause inflammation, and dead worms can block blood flow in the heart and lungs, leading to serious complications.

3. Post-Treatment Care: After adulticide treatment, dogs must be kept on strict rest for several weeks to prevent complications such as blood clots or embolisms. During this time, the dog may experience side effects like fever, coughing, and lethargy as the dead worms are absorbed by the body.

4. Follow-up Testing: After treatment, dogs will need to be monitored regularly with blood tests to ensure that all adult heartworms have been eradicated. This typically involves testing at the 6-month and 12-month marks.

5. Surgical Intervention: In cases of severe infection, surgery may be necessary to remove large numbers of heartworms from the dog’s heart and lungs. This is a rare and more invasive treatment option, often reserved for the most severe cases.

Heartworm disease is a serious concern for dog owners in Georgia due to the state's warm climate, high mosquito activity, and the prevalence of the disease. The key to protecting your dog is prevention — year-round use of heartworm preventives and regular vet check-ups. If heartworm disease is diagnosed, early treatment can help save a dog’s life, though the process can be costly and challenging. By staying informed and taking proactive steps, dog owners can ensure that their pets remain healthy and heartworm-free.

This summer, the Comer Vet team says, "No heartworms allowed!"

Shield your pet from this mosquito-borne parasite by purchasing 12 months of heartworm prevention (or, if your pet is eligible, an annual ProHeart shot) and you'll get your choice of a FREE heartworm test OR 10 percent off your pet's annual bloodwork! This special only runs from June 1 to July 31, so give us a call now to order your yearly heartworm medication and schedule a prevention appointment!

Please note this offer does not apply to online heartworm prevention orders; to receive your free heartworm test or bloodwork savings, annual heartworm prevention must be purchased in-person or over the phone through Comer Vet.

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