The Importance of Heartworm Testing and Prevention

3 min read

As pet owners, keeping our furry friends safe from preventable diseases is one of the best ways we can protect their health—and our wallets. Heartworm disease is one of the most serious and costly illnesses affecting dogs (and sometimes cats), yet it’s almost entirely preventable with the right care.

If your pet isn’t already on year-round heartworm prevention, your veterinarian will likely recommend a heartworm test before starting treatment. In this post, we’ll explain why testing is essential, how prevention works, and how taking action now can save you—and your pet—from a life-threatening problem later.

Why Heartworm Testing Matters

Heartworm disease is caused by a parasite transmitted through mosquito bites. Once inside your pet’s body, the worms grow in the heart, lungs, and blood vessels, causing severe damage. By the time symptoms appear—such as coughing, fatigue, and weight loss—the disease may already be advanced.

Testing is crucial for two main reasons:

1. Silent Early Stages – Heartworms can be present for months without obvious symptoms.

2. Safe Prevention – Giving preventive medication to a pet that already has heartworms can be dangerous. Testing ensures the medication will be safe and effective.

   
   

The American Heartworm Society recommends testing dogs annually, even if they’re on prevention, to ensure no infections have occurred. Cats, while less commonly infected, can also be tested—especially if they spend time outdoors.

How Heartworm Prevention Works

Heartworm prevention medications—available as monthly chewables, topical solutions, or injections—work by killing immature larvae before they can develop into adult worms. These medications do not kill adult worms, which is why consistent prevention and annual testing are critical.

Prevention options include:

• Monthly Chewables – Flavored tablets your pet can take at home.

• Topical Medications – Applied to the skin, often combining flea/tick protection.

• Injections – Long-lasting shots given by your vet (every 6 or 12 months).

💡 Tip: Skipping just one dose—or giving it late—can leave your pet unprotected.

Steps to Protect Your Pet

1. Schedule a Heartworm Test - Ask your veterinarian for a quick, in-office test. Results are usually available within minutes.

2. Choose the Right Prevention - Discuss with your vet which form—chewable, topical, or injection—best fits your pet’s lifestyle and your budget.

3. Use a Prescription Discount Card - Heartworm preventives can often be filled at local pharmacies for less. Use a prescription discount card to compare prices and save up to 50% or more.

4. Stay Consistent - Set reminders on your phone or mark your calendar so you never miss a dose.

   
   

Important Considerations

• Indoor Pets Still Need Protection – Mosquitoes can get inside, so even indoor pets are at risk.

• Treatment is Expensive and Risky – Treating heartworm disease can cost over $1,000 and involves months of restricted activity. Prevention is safer and far less expensive.

• Regional Risks Vary – In warm, humid areas (like much of the U.S. South), the risk is year-round.

  
  

Advantages of Year-Round Heartworm Prevention

💵 Lower Costs – Prevention costs a fraction of treatment.

🛡 Peace of Mind – Protects against a deadly but preventable disease.

🏃 Keeps Pets Active – Healthy pets can enjoy life without months of recovery.

By making heartworm testing and prevention a routine part of your pet’s care, you’re giving them the gift of a healthier, longer life—without the risks and costs of this dangerous disease.