What are Heartworms & How do I Protect My Dog?


dog with the vet getting checked for heartworms

Pets are just like family to us. We never want to see our bundle of cuddle be in pain or suffering from preventable diseases. As pawrents, we are always taking care of them, giving them the best attention and protecting them. If you want to avoid a serious health condition in your dog, you should know about heartworm disease.

Apart from being fatal, the treatment of heartworm disease is quite expensive. So, it is better to prevent it beforehand. We have included a detailed guideline on heartworm disease including its causes, signs, and symptoms, prevention, and treatment.


What is heartworm?

Heartworm is a potential disease common among pets like cats, dogs, foxes, and ferrets. More common in dogs as they are natural hosts of heartworms. It is a condition in which a parasite, named Dirofilaria immitis or commonly known as heartworm, infects the pet and leads to serious health conditions. These parasites get into the bloodstream of the host and affects the lungs and heart. It attacks the blood vessels connecting the lungs to the heart known as pulmonary vessels. It may cause damage to the other organs as well.


How does a dog get heartworm disease?

It’s starts with a mosquito bite. Heartworm is a non-contagious disease, means it cannot be transferred from one dog to another by contact.


The heartworm is transferred when a mosquito bites a dog that has disease, and then the same mosquito bites other healthy dogs. The mosquito sucks the blood and draws up the tiny larvae, also known as microfilariae, from the infected dog, and that larvae develops inside the mosquito for 10-15 days. When this microfilaria is transferred from the mosquito to a dog, it can mature into adult heartworms inside the dog’s body. Microfilariae particularly develops in the bloodstream and then travels to the chambers of the heart and lungs.

lifecycle of the heartworm inside dogs shown in a circle chart
Photo credit: PetMD

Signs and Symptoms

At an early stage, your dog will show slight symptoms to no symptoms at all. The symptoms appear as the disease progresses. The slight signs and symptoms that may occur at an earlier stage include:

  • Persistent cough

  • Fatigue

  • Unable to move or resistant to exercise

  • Weight loss

  • Loss of appetite

However, in severe cases when the disease has progressed, the signs and symptoms may include:

  • Difficulty in breathing

  • Anemia

  • Muscle atrophy

  • Swollen belly

  • Dark colored urine

  • Fluid accumulation in lungs

  • Scar tissue in lungs

  • Caval syndrome or Heart failure at the last stage


4 Ways to Prevent Heartworm Disease

Prevention is always the best method of protection for your dog(s). Here are some preventive measures that you may take to protect your pup from such a fatal disease.

dog at vet for checkup on heartworms

Regular Checkup and Diagnostic Tests

To prevent the disease, a routine checkup is necessary. It is recommended by the American Heartworm Society to get your dog tested for heartworm disease by a vet at least once a year.


Blood tests are indicated to diagnose heartworms in your dog's bloodstream. There are two tests used to confirm the diagnosis. An antigen-specific test detects chemicals released by adult heartworms. Another test detects microfilariae in the bloodstream. But unfortunately, these tests only show positive 5-6 months after getting infected by the parasite.

Avoid Mosquito Exposure

As the disease spreads by a mosquito bite, there's nothing better than avoiding mosquito exposure to your dog. For this, you can avoid the areas where a dog can contact mosquitos, like in the lawn or nearby parks. Avoid taking your dog for a walk during dusk or dawn as mosquitos are the most active during these hours.

mosquito can carry heartworms

Use mosquito repellents. Neem oil may help in this regard. Avoid stagnant water as mosquitoes breed there. Make sure to clean your pup’s water bowl. It can reduce the number of mosquitoes near the dog’s home.


It will be nearly impossible to avoid all mosquitoes if you live in the south. That is why preventative measures, like medications, are still necessary for all dogs. But you can avoid the majority of mosquitoes to reduce the risk of your dog getting bit.


Preventive Medications

FDA recommends preventive medications for heartworms in dogs. These are available in the form of oral, topical, and intravenous. It is necessary to take a vet's advice before using any medication. So, talk to your vet and take preventive medicines specific to the weight and size of your dog.

dog eating healthy food to prevent heartworm

Provide a Good Diet

The least you can do is to provide your dog with a good diet. Make sure the food you provide has all the vitamins, minerals and supplements needed for the breed, age, and size of your dog. Try to give him home-cooked meals instead of buying dog food at the store. If it is impossible to cook the food by yourself, find dog food from a good brand that has a balance of carbs, proteins, and minerals in it. Good nutrition will boost his immunity and make him prepare to fight any infection coming his way.


My dog lives inside, why do I need prevention?

dogs laying in bed can still have heartworm risk

Your dog is always going to be at risk if they live in an area that has mosquitoes. They only need to be bitten one time for heartworms to be transferred. This means, even if they live inside, going outside to go to the bathroom can allow that one mosquito to get them. Also, mosquitoes can still fly inside the home. Would you want to risk your pup's health for something that can be easily prevented?


Did your dog become diagnosed with heartworms?

If your dog’s diagnosed for heartworm disease, don’t panic. Here are few guidelines to follow.


Stage of the Disease

Your dog might be in a lot of discomfort and needs appropriate stabilization therapy. The first thing you have to be sure of after confirming the diagnosis is the stage of the disease. This will be determined by the vet and help them decide the next steps in stabilizing the dog's condition. A complete checkup including chest x-ray, complete blood count, urinalysis, and echocardiogram is advised.


dogs need rest when treating heartworm disease

Complete Rest

It is necessary to restrict exercise in your dog as it might put excessive stress on the heart which is already dealing with the worms. Physical activity can increase the rate of damage to the heart by heartworms. It might be difficult to stop your dog from running here and there so you can get calming medicine from your vet to help with complete rest. It is important during and after the treatment too. Your vet can advise you on the amount of time your dog needs to be on treatment and rest.


Administer Medicine

Dogs who have no to mild symptoms can be treated with at home medication. The vet may administer corticosteroids to reduce the serious effects of the disease. Make sure to follow the prescribed guidelines. Do not stop the medication even if the symptoms disappear. Medication period can last for a couple months to a year depending on severity of the disease.


The dog may get admitted to the hospital for a day or two if oral medication is not effective.


Surgery May be Required

In severe cases, surgery may be required to treat the potential disease, but it can have greater complications. A surgical procedure will be done to remove the heartworms from the blood vessels of the heart and lungs.


Prevent Recurrence

A confirmatory test to detect juvenile heartworms in the bloodstream is done after thirty days of administering medication. Your dog will be tested nine months after the treatment if they have adult heartworms. It will not only diagnose the success of the treatment but also prevent the recurrence of the disease.


Also, don't forget to administer the preventive medication!


Complications After Treatment

Complications are common after treatment of heartworm, that’s why it is recommended to prevent the disease instead relying on treatment. Usually, you want to choose the slow kill method to reduce the stress on the body. The fast kill method can create a wide range of complications.


Steroids have serious side effects that need to be avoided. Some of them include:

  • Swelling at the injection site, particularly on the side of the spine

  • Pain and discomfort

  • Abscess formation

  • Loss of appetite

  • Vomiting or diarrhea

  • Fatigue or lethargy

  • Persistent cough or even difficulty in breathing.

The only solution to save your dog from these side effects is to take preventive measures and make sure to administer the monthly dose of preventive medication recommended by the FDA.


How can I help my pup holistically?

acupressure on dog boosts immune system

Acupressure

You can always boost the immune system with acupressure.