Heartworm Treatment Guidelines for Pet Owners: What Are the Basics?

heartworm treatment

According to the American Veterinary Medical Association (AVMA), heartworm disease incidence rates are on the rise. This uptick is occurring both in previously-known hotspots, as well as locations with historically low numbers. 

Heartworm disease is a serious and potentially fatal condition for both dogs and cats, though it is more common in dogs. It can cause worms to grow in their hearts, lungs, and blood vessels, which can lead to a host of conditions, including lung disease and heart failure. 

Thankfully, there are heartworm prevention solutions that can help remove these parasites and help pets stay healthy. Today, we’re taking a look at how these preventions work and sharing everything responsible pet owners need to know. 

Heartworm treatments and or medications are important for the care of your pet.  Being proactive with treatments and preventative medications, with the advice of your pet’s veterinarian, will help keep parasites at bay.

What Is Heartworm Disease?

Heartworm disease is a medical condition that starts with a blood-borne parasite called Dirofilaria immitis. Mosquitoes can act as a host for this parasite, transferring it into an animal through a bite

Thus, heartworm disease is most often associated with the summer season, when mosquitoes are most prevalent and active. However, in many parts of the U.S., including Indiana, these pests are a year-round occurrence. 

If a mosquito carrying Dirofilaria immitis bites a dog, it can negatively affect their health. In infected pets, adult heartworms commonly grow in the circulatory system:

  • Heart
  • Pulmonary artery
  • Large blood vessels

Female worms can grow up to 14 inches long, while males are about half this size. Both males and females can live for up to five years, and one infected dog can have as many as 300 individual worms present at the time of diagnosis. 

As they develop, female worms reproduce at a rapid rate. Their larvae, called microfilariae, live in the pet’s small blood vessels. When a mosquito feeds on the blood of an infected dog, it can ingest these microfilariae and spread the infection to another dog with a subsequent bite. 

Symptoms of Heartworm Disease

In the early stages of heartworm disease, pets may show no symptoms at all. However, they can develop as the condition persists. 

Some of the most common signs of heartworm in dogs include:

  • No signs at all
  • Mild, constant cough
  • Decreased appetite
  • Fatigue after moderate exercise
  • Reluctance to exercise 
  • Weight loss

As the disease worsens, pets may develop excess fluid in their abdomen. They may also experience heart failure.

When heartworms are present in large quantities, they can block the flow of blood to the animal’s heart. This leads to a sudden, life-threatening cardiovascular condition called Caval Syndrome. 

Types of Heartworm Treatment 

By the time dogs begin showing signs of heartworm disease, most are already in an advanced stage of the condition. This means that the heartworms have started to cause significant damage to many of their organs, including:

  • Lungs
  • Heart
  • Blood vessels
  • Liver
  • Kidney

Your veterinarian will be able to assess the degree of heartworm disease present. From there, they will recommend certain treatments designed to kill the worms and restore your pet’s health and quality of life. These treatments will be in line with the latest recommendations from the American Heartworm Society. 

Treating or Preventing the Microfilariae

The first thing we want to do is try to prevent your pet from ever having adult worms. There are several options to prevent heartworm disease including oral, injectable, and topical preventions. This is the best and most safe way to protect your pet. This is also the least expensive option. Always ask your veterinarian what option is the best for your pet. 

Treating the Adult Heartworms

Killing adult heartworms normally requires a series of three injections of a medication called melarsomine. This drug kills any adult heartworms living in your dog’s heart and adjacent blood vessels. 

Your veterinarian will determine how to schedule the injections based on your pet’s condition. Most dogs need about one month of rest time after their first injection. After that initial break, the next two injections are given 24 hours apart. 

Your pup might be required to stay in the veterinary office or hospital for observation on the day they receive the injection. Some pets are also treated with an antibiotic to help eliminate the bacteria that can inhabit the heartworms.

Advanced Cases

In some rare cases, heartworm disease has progressed so extensively in a pet that their veterinarian may choose to treat their organ damage rather than risk any negative effects that might occur from a more targeted treatment. 

If melarsomine is used to treat an advanced case, your vet may prescribe additional medications to keep them comfortable, including: 

  • Corticosteroids
  • Antibiotics
  • Pain relievers
  • Diuretics (to remove fluid from the lungs)
  • Drugs to improve heart function

In addition, your vet might require your pup to follow a special diet to optimize their health before, during, and after the heartworm treatment. 

Potential Side Effects

After each injection, you may also notice your pet coughing more than usual. This is a normal side effect of this medication that can last several weeks. 

However, it’s important to call your vet if you notice your dog experiencing a severe reaction to the heartworm medicine. This can include any of the following symptoms:

  • Loss of appetite
  • Shortness of breath
  • Fever
  • Coughing up blood
  • Severe coughing 

Your vet can prescribe medication, along with at-home changes such as supportive care and cage rest, to help them recover. 

The Importance of Rest

While your pet is undergoing heartworm treatment, it’s important not to overstimulate them. A few days after the initial injection, adult worms will begin to die and decompose. 

As they do so, they travel to the lungs and into your dog’s small blood vessels, where they’ll eventually reabsorb into their body. This reabsorption period is critical to a successful treatment, but those fragments of dead worms can also be dangerous for your dog if they don’t travel to the right locations. 

Don’t engage your pet in any rigorous activity, especially during that first 30-day rest period. Try to keep them as quiet as possible and encourage rest. 

Learn More About Heartworm Treatment

Are you worried that your four-legged pal might be suffering from heartworms? In most cases, this condition is treatable as long as you know what to do and where to go. In addition to heartworm treatment options discussed above, there are also preventative medications you can talk to your veterinarian that are available to help keep these parasites at bay.

At All Animals Veterinary Clinic, we’re here to help your pets feel their best. We provide services for large and small animals, throughout every stage of life. To learn more and schedule an appointment, contact us today!

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