How to Protect Your Dog from Heartworms

Heartworm disease is a serious and potentially fatal condition caused by parasitic worms that reside in a dog’s heart and lungs. These parasites, specifically Dirofilaria immitis, are transmitted through mosquito bites and can cause significant damage to your dog’s organs.

Unfortunately, heartworm disease is widespread, and any dog that is not properly protected can become infected. The good news is that heartworm disease is entirely preventable with proper care and proactive measures.

In this article, we will explore the causes of heartworm disease, the symptoms, diagnosis, treatment options, and most importantly, how to protect your dog from heartworms. By following preventative measures and ensuring your pet’s health is regularly monitored, you can greatly reduce the risk of heartworm disease and help keep your dog healthy and happy.

What Are Heartworms?

Heartworms are parasitic worms that live inside the heart, lungs, and blood vessels of infected dogs. The worms can grow up to 12 inches long, and a single dog can host many heartworms. These parasites are transmitted by mosquitoes, which carry microscopic larvae (called microfilariae) from infected dogs. When an infected mosquito bites a healthy dog, it transmits the larvae into the dog’s bloodstream, where they eventually mature into adult heartworms.

Over time, heartworms can cause severe damage to the heart and lungs, leading to heart failure, organ damage, and in some cases, death. The disease is slow to develop, so a dog may not show signs of infection until the damage is severe.

The Dangers of Heartworm Disease

Heartworm disease can cause a variety of severe health problems, including:

1. Heart Failure: The adult heartworms live in the heart, where they can block blood flow and damage the heart’s ability to pump effectively. This can lead to congestive heart failure.
2. Lung Damage: As the worms move through the dog’s lungs, they can cause inflammation and scarring, leading to difficulty breathing, coughing, and even pneumonia.
3. Organ Damage: In severe cases, the heartworms can damage other organs, including the liver and kidneys, leading to organ failure.
4. Death: If left untreated, heartworm disease can be fatal. Infected dogs often die from complications such as severe heart failure, lung damage, or organ failure.

The good news is that heartworm disease is preventable with regular preventative care. The best way to protect your dog is through consistent use of heartworm prevention medications.

How Is Heartworm Disease Transmitted?

Heartworms are transmitted through mosquito bites. When a mosquito feeds on the blood of an infected dog, it picks up microfilariae (larvae). After about 10 to 14 days, the larvae mature in the mosquito’s body, becoming infective. When the mosquito bites another dog, it injects the larvae into the dog’s bloodstream, where they travel through the bloodstream and eventually reach the heart and lungs, where they grow into adult heartworms.

Because heartworms are transmitted by mosquitoes, any dog in a mosquito-prone area is at risk. This includes both outdoor and indoor dogs. Even dogs that spend most of their time inside are at risk, as mosquitoes can find their way inside homes.

Symptoms of Heartworm Disease

Heartworm disease often progresses slowly, and early symptoms may not be obvious. However, as the infection worsens, your dog may show signs of illness. Some common symptoms include:

1. Coughing: A persistent cough, especially after exercise or during the night, is one of the first signs of heartworm disease.
2. Fatigue or Weakness: Dogs with heartworm disease may become tired quickly, struggle to exercise, or seem unusually lethargic.
3. Difficulty Breathing: Heartworms can damage the lungs, causing difficulty breathing, labored breathing, or rapid breathing.
4. Loss of Appetite: Infected dogs may lose interest in food or show signs of nausea.
5. Weight Loss: As the disease progresses, dogs may experience weight loss due to reduced appetite and the body’s inability to absorb nutrients properly.
6. Swollen Belly: In severe cases, heartworm disease can lead to fluid accumulation in the abdomen, which causes a swollen or bloated belly.
7. Collapse or Fainting: Advanced heartworm disease can lead to heart failure, resulting in episodes of fainting or collapse, especially after exercise.

If you notice any of these symptoms in your dog, it’s important to seek veterinary care immediately. Early detection and treatment can help improve the outcome and reduce the risk of severe damage.

Diagnosing Heartworm Disease

If your dog is showing symptoms of heartworm disease, your veterinarian will perform a series of tests to diagnose the condition. The most common tests include:

1. Blood Tests: A blood test can detect the presence of heartworm antigens or microfilariae in your dog’s bloodstream. This is typically the first step in diagnosing heartworm disease.
2. X-Rays: X-rays can help determine the extent of damage to the heart and lungs. This can give your vet a better idea of how advanced the disease is.
3. Ultrasound: In some cases, an ultrasound of the heart may be necessary to identify adult heartworms and assess the level of damage to the heart.
4. ECG (Electrocardiogram): An ECG can help evaluate the heart’s electrical activity, which can be affected by heartworm disease.

Treatment for Heartworm Disease

Treatment for heartworm disease is complex and can be expensive. The primary treatment method is a series of injections with a medication called melarsomine, which kills adult heartworms. This treatment is typically done in several stages over a few months, and it carries risks, such as complications from dying worms, which can cause inflammation and other issues in the lungs or heart.

During treatment, dogs must be kept quiet and restricted from exercise to avoid complications, as the dying worms can create blockages and cause damage to the heart and lungs.

Because treatment can be dangerous, time-consuming, and expensive, prevention is always the best course of action.

READ ALSO: What Do Fleas Look Like? Understanding the Tiny Parasites

How to Prevent Heartworm Disease

Preventing heartworm disease is much easier (and cheaper) than treating it. There are several methods to protect your dog from heartworms, with the most effective being heartworm prevention medications. These medications come in various forms, including:

1. Oral Medications
   Oral heartworm preventatives, such as Heartgard Plus, Sentinel, or Interceptor, are typically given once a month. These medications contain ingredients that kill the larvae before they can mature into adult heartworms. These preventatives are easy to administer and are usually flavored to appeal to pets.
2. Topical Treatments
   Some products, such as Revolution, are applied directly to the skin once a month. These topical treatments also prevent heartworm infection and offer protection against other parasites, like fleas and ticks.
3. Injectable Preventatives
   The injectable heartworm preventative, ProHeart 12, provides protection for up to 12 months with a single injection. This option is ideal for pet owners who have trouble remembering monthly treatments or for dogs that are resistant to oral or topical medications.
4. Combination Products
   Some preventatives also protect against additional parasites, such as fleas, ticks, and intestinal worms. Combination medications can simplify parasite control by protecting your dog against multiple threats with a single product.

When to Start Heartworm Prevention

Heartworm prevention should begin early in your dog’s life, ideally starting at 6 to 8 weeks of age. Even if your dog is older, it’s never too late to start preventing heartworm disease. If you are adopting a dog from a shelter, make sure they are tested for heartworms before starting prevention.

In addition to starting prevention early, it’s crucial to keep your dog on a consistent schedule. Missing doses or failing to give monthly prevention can leave your dog vulnerable to infection. Make sure to set reminders so you never miss a dose.

FAQs

Can indoor dogs get heartworms?

Yes, even indoor dogs can get heartworms if they are exposed to mosquitoes that enter the home. That’s why year-round prevention is important for all dogs, regardless of whether they are indoors or outdoors.

What happens if I miss a dose of heartworm prevention?

If you miss a dose, give it as soon as you remember, but don’t double the dose. If more than a month has passed, consult your vet about when to give the next dose. You may need to have your dog tested for heartworms before resuming prevention.

Can heartworm prevention prevent other parasites?

Yes, many heartworm preventatives also protect against fleas, ticks, and intestinal worms, making them a comprehensive parasite control solution.

Are there side effects to heartworm prevention?

Most heartworm preventatives are safe and well-tolerated, but some dogs may experience mild side effects such as vomiting or diarrhea. If you notice unusual symptoms, contact your vet.

How often should my dog be tested for heartworms?

Your dog should be tested for heartworms annually, even if they are on prevention. This ensures that any possible infections are detected early.