Best Heartworm Preventive Medicines for Dogs

10 Best Heartworm Medications for Dogs – Vet Picks + Product Comparison

Edward Simmons

"Just one mosquito bite can lead to months of treatment and hundreds in vet bills."

This stark reality highlights the silent danger lurking in every backyard. But what exactly does this mean for your dog's health, and why is staying ahead of heartworm disease so critical in 2025?

Heartworm disease, caused by the parasite Dirofilaria immitis, is a serious and potentially fatal condition for dogs. It's transmitted through the bite of infected mosquitoes, and these insidious parasites can grow in a dog's heart, lungs, and associated blood vessels. 

📌 TL;DR – Best Heartworm Medications for Dogs

  • Heartworm is deadly but 100% preventable with consistent monthly medication.
  • Mosquitoes are the only transmitters—and they’re more active due to climate change.
  • Indoor dogs are still at risk because mosquitoes enter homes.
  • Vet-recommended preventatives include:
    • Simparica Trio – All-in-one protection (fleas, ticks, worms)
    • Heartgard Plus – Affordable core protection
    • Interceptor Plus – Broad intestinal worm coverage
  • Always test for heartworm first before starting any medication.
  • Prevention is safer and cheaper than treating active infections.
  • Monthly dosing is critical—missing even one dose increases risk.
  • Choose based on: breed sensitivity, health conditions, region, and product form (chew vs. topical).

This infestation can lead to severe lung disease, heart failure, and ultimately, death if left untreated. Learn more about the progression, treatment stages, and costs in our comprehensive guide on heartworm disease in dogs.

What Makes Heartworm Prevention Critical in 2025?

  • Climate Change Impact: Warmer temperatures and changing weather patterns are expanding the geographical range and mosquitoes’ lifespan, the sole carriers of heartworm. The Centers for Disease Control and Prevention (CDC) notes that vector-borne diseases, including those transmitted by mosquitoes, are a growing public health concern. Source: CDC - Climate Change and Health

Changing seasons and shifting parasite zones require a more nuanced prevention approach—this pet parasite prevention guide explains how to adapt in 2025.

  • Increased Incidence: This expansion means more dogs are at risk, even in areas that were considered safe previously. While specific national statistics fluctuate, veterinary professionals consistently report an uptick in positive cases across various regions.

Prevention is Paramount:

  • Treatment Is Risky, Expensive, and Slow: Heartworm treatment involves toxic injections, antibiotics, and months of inactivity. Costs can exceed hundreds or even thousands of dollars.
  • Prevention is Safer: Heartworm preventatives are safe, highly effective, and often provide broad-spectrum protection. Many products also guard against:
    • Fleas
    • Ticks
    • Intestinal worms (like roundworms and hookworms)

At HardyPaw, we understand the critical importance of this proactive approach. We are here to guide you through the top heartworm preventative medications for dogs in 2025, ensuring your canine companion remains healthy and protected throughout the year. Let's get started!

10 Best Heartworm Medications for Dogs in 2025 [Vet-Recommended]

Veterinarians recommend heartworm preventatives based on clinical efficacy, multi-parasite coverage, breed compatibility, and compliance. 

Below is a detailed comparison of 10 of the most trusted, vet-approved preventatives available in 2025 - suited for multiple dog breeds, lifestyles, and health profiles.

1. Simparica Trio for Dogs

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: Vets often recommend Simparica Trio for households in high-risk regions where dogs are exposed to multiple parasites year-round. It simplifies protection and improves compliance in busy families.

2. Heartgard Plus for Dogs

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: Heartgard Plus is our go-to for reliable heartworm prevention. We typically pair it with a separate flea/tick product to create a customized parasite control plan for each dog.

Still weighing your options? Dive into our side-by-side Simparica Trio vs Heartgard Plus comparison to better understand which one fits your pup’s needs.

3. Interceptor Plus for Dogs

  • Form: Monthly chewable
  • Protects Against: Heartworm, roundworms, hookworms, whipworms, tapeworms
  • Best For: Dogs at risk for intestinal parasites, including tapeworms
  • Pros: Comprehensive intestinal worm coverage; great for outdoor dogs
  • Cons: Lacks flea and tick protection
  • Pricing (1 Chewable tablet): The average cost of Interceptor Plus varies between $11- $14 based on the dog’s weight and age.
    • Interceptor Plus for Puppies (2–8 lbs): $11.48
    • Interceptor Plus for Small Dogs (8.1–25 lbs):$11.48
    • Interceptor Plus for Medium Dogs (25.1–50 lbs): $12.58
    • Interceptor Plus for Large Dogs (50.1–100 lbs):$13.98

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: Especially valuable in rural areas where dogs are exposed to wildlife and zoonotic parasites. They also recommend it for multi-pet households with elevated hygiene needs.

4. Credelio Quattro for Dogs

Credelio Quattro Flavored Chewable Tablets for Dogs, 12.1 to 25 lbs, 3 tablets

  • Form: Monthly chewable
  • Protects Against: Heartworm, fleas, ticks, roundworms, hookworms, whipworms
  • Best For: Pet parents wanting the latest, all-in-one oral protection
  • Pros: Broad-spectrum control in a single chew; newly formulated for improved digestibility
  • Cons: Early in rollout; availability may be limited in some clinics
  • Pricing (1 Chewable tablet): The average cost of Credelio Quattro varies between $32 - $37 based on the dog’s weight and age. 
    • Credelio Quattro Flavored Chewable Tablets for Dogs & Puppies, 3.3 to 6 lbs – $32.48
    • Credelio Quattro Flavored Chewable Tablets for Dogs, 6.1 to 12 lbs – $32.98
    • Credelio Quattro Flavored Chewable Tablets for Dogs, 12.1 to 25 lbs – $33.48
    • Credelio Quattro Flavored Chewable Tablets for Dogs 25.1 to 50 lbs – $35.98
    • Credelio Quattro Flavored Chewable Tablets for Dogs 50.1 to 100 lbs – $36.98

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: As a newly FDA-approved 2025 product, Credelio Quattro is quickly gaining favor for its broad parasite spectrum and appeal to dogs with picky palates. It's ideal for tech-savvy pet parents looking for next-gen protection.

5. Advantage Multi for Dogs

Advantage Multi 88.1-110 lbs, Brown 12 months

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: A great non-oral alternative that offers robust worm protection. It’s commonly recommended for toy breeds or dogs with dental issues or GI sensitivities.”

6. Revolution Topical Solution for Dogs

Revolution for Dogs 20.1-40 lbs 3 dose

  • Form: Monthly topical
  • Protects Against: Heartworm, fleas, American dog tick, ear mites, and mange
  • Best For: Small or sensitive dogs with ear or skin issues
  • Pros: Gentle formula; ear mite and mange control included
  • Cons: No whipworm or tapeworm protection
  • Pricing: The average cost of Revolution Topical Solution for Dogs (single dose) ranges from $32.38 - $45.34
    • Revolution Topical Solution for Dogs 5.1-10 lbs (Purple) - $32.38
    • Revolution Topical Solution for Dogs 10.1-20 lbs (Brown) - $33.00
    • Revolution Topical Solution for Dogs 20.1-40 lbs (Red) - $35.62
    • Revolution Topical Solution for Dogs 40.1-85 lbs (Teal) - $35.62
    • Revolution Topical Solution for Dogs 85.1-130 lbs (Plum) - $45.34

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: We frequently use Revolution for dogs with dermatological issues. It's mild, effective, and particularly suited for sensitive breeds like Yorkies, Maltese, and poodles.

7. Sentinel Spectrum Chews

Sentinel Spectrum Chews for Dogs 50.1-100 lbs 12 chewables

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: Sentinel Spectrum is particularly useful for preventing flea infestation cycles. It’s an ideal choice for families with young children, where parasite cross-contamination is a concern.

8. Trifexis Chewable Tablets

Trifexis for Dogs 40.1-60 lbs 12 chewable

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: “Trifexis is great for dogs who need fast flea kill and robust worm protection. We typically advise giving it with food to reduce the risk of GI upset.”

9. Parasedge Multi for Dogs

Parasedge Multi for Dogs 55.1-88 lbs 6 dose

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: Parasedge Multi is a smart option when affordability is a priority. We recommend it for dogs who can’t handle oral meds but still need full internal protection.

10. Iverhart Plus Chewable Tablet

iVERHART PLUS AT HARDYPAW

[Note: Actual pricing may vary over time. Please check the product page for the most up-to-date pricing information.]

  • Vet Insight: A solid option for dogs who don’t need intense parasite protection. We use it selectively based on region and exposure.

Top Heartworm Medicines for Dogs - Comparison Table 

Product

Form

Protects Against

Best For

Pros

Cons

Simparica Trio

Chewable

Heartworm, fleas, ticks, roundworms, hookworms

All-in-one simplicity

Full parasite coverage in one chew

Higher cost, not for MDR1-sensitive breeds

Heartgard Plus

Chewable

Heartworm, roundworms, hookworms

Basic protection with good palatability

Trusted, budget-friendly

No flea/tick/tapeworm protection

Interceptor Plus

Chewable

Heartworm, roundworms, hookworms, whipworms, tapeworms

Dogs are at risk for intestinal worms

Broad worm coverage

Needs a separate flea/tick product

Credelio Quattro

Chewable

Heartworm, fleas, ticks, roundworms, hookworms, whipworms

Modern all-in-one users

Newest oral combo option

Limited clinic availability at launch

Advantage Multi

Topical

Heartworm, fleas, roundworms, hookworms, whipworms, sarcoptic mange

Dogs are intolerant of oral meds

Great for GI-sensitive pets

No tick protection

Revolution

Topical

Heartworm, fleas, American dog tick, ear mites, sarcoptic mange

Small breeds, skin/allergy-prone dogs

Gentle topical ear mite treatment included

No whipworm or tapeworm protection

Sentinel Spectrum

Chewable

Heartworm, roundworms, hookworms, whipworms, tapeworms, flea sterilization

Family homes with flea risk

Excellent intestinal worm coverage

Doesn’t kill adult fleas or ticks

Trifexis

Chewable

Heartworm, fleas, roundworms, hookworms, whipworms

Fast flea kill + deworming

Great for flea-prone regions

Possible GI side effects

Parasedge Multi

Topical

Heartworm, fleas, roundworms, hookworms, whipworms, sarcoptic mange

Budget-conscious topical users

Cost-effective, internal coverage

No tick protection; oily application

Iverhart Plus

Chewable

Heartworm, roundworms, hookworms

Minimalist users with low parasite exposure

Simple, inexpensive worm control

No coverage beyond basic worms

Now that you've seen the top products side-by-side, you're probably wondering: how do veterinarians decide which preventative is the right fit for each individual dog?

It’s not a one-size-fits-all approach. Vets take into account a range of personalized factors—some clinical, some environmental—to match each dog with the safest and most effective protection strategy.

What Factors Do Vets Consider Before Prescribing Heartworm Prevention?

Let’s explore the key decision points vets evaluate before prescribing any heartworm prevention plan:

  • Breed-Specific Sensitivities : Some breeds, particularly herding breeds like Collies, Australian Shepherds, and Shelties, carry the MDR1 gene mutation, which makes them sensitive to certain macrocyclic lactones (like ivermectin). Vets often conduct genetic testing or steer toward moxidectin-based products for safety.
  • Age, Weight & Health Profile: Preventatives come with minimum age and weight thresholds, and some products are not recommended for puppies, pregnant dogs, or senior pets with liver, kidney, or heart conditions. Your vet reviews your dog’s medical history and current meds to avoid contraindications.
  • Regional Parasite Exposure: If you live in a flea- or tick-heavy state (like Florida, Texas, or parts of the Midwest), your dog may need a broad-spectrum product that includes ectoparasite protection. Rural dogs may face exposure to whipworms or tapeworms, while urban dogs might need more internal control.
  • Owner Lifestyle & Dosing Preferences: Vets assess your ability to maintain a monthly schedule. Are you forgetful? An injectable or long-acting topical may be better. Have kids in the home? A non-messy oral option might be safer. Ease of administration is key to long-term compliance.

Understanding how veterinarians choose a product is just one part of the puzzle. The next step is ensuring it’s used safely and consistently.

Vet Tips for Safe and Effective Use of Heartworm Preventatives 

Even the most advanced medication won’t protect your dog if it's skipped, dosed incorrectly, or started without proper testing. That’s why vets emphasize a few crucial practices every dog owner should follow to maximize protection and minimize risk.

Here’s what experts advise:

1. Always Begin with a Heartworm Test: Before starting (or restarting) any heartworm preventative, your dog must test negative for heartworms. This is non-negotiable. Preventatives kill the larval stage (microfilariae)—not adult heartworms. If adult worms are present, initiating medication can lead to life-threatening shock from worm die-off reactions.

2. Administer on a Strict Monthly Schedule: Timing matters. Most oral and topical preventatives are effective for 30 days only. Missing even one dose can allow larvae to mature into adults. Vets recommend setting calendar reminders or syncing doses with a memorable date (like your dog’s birthday).

3. Watch for Side Effects, Especially with New Medications: While most preventatives are well-tolerated, mild side effects like vomiting or lethargy can occur—especially with new products. Monitor your dog closely during the first 24 hours after administration and report any unusual behavior to your vet.

4. Adjust Your Product as Your Dog Ages or Changes Weight: Puppies grow. Seniors develop health concerns. Seasonal shifts alter parasite exposure. Vets recommend re-evaluating your prevention plan at every annual checkup to ensure continued safety and effectiveness.

5. Don’t Substitute or Share Between Pets: Products are dosed by weight and species. Giving your large dog’s pill to a smaller pup or to a cat can be dangerous—even fatal. Always follow label instructions and never repurpose medication across pets.

Final Takeaways on Dog Heartworm Medications

Heartworm disease is preventable, but only when prevention is timely, consistent, and tailored to your dog’s needs. With so many options available in 2025, choosing the right product comes down to understanding your dog’s health, your environment, and your ability to stay on schedule.

At HardyPaw, we simplify that choice by offering a curated selection of vet-recommended heartworm preventatives—so you can shop confidently, knowing every product we carry meets rigorous safety and efficacy standards.

Ready to protect your pup? Browse our dog heartworm prevention collection and take the first step toward a heartworm-free year.

Best Dog Heartworm Medications FAQs

Can heartworm be transmitted from dog to dog?

No, heartworm is transmitted only through mosquito bites; dogs can't infect each other directly.

Can I buy heartworm preventives without a vet prescription?

No. In the United States, heartworm preventives are available by vet prescription only. 

How long does heartworm prevention take to work?

Heartworm preventatives start working within hours and kill larvae from the past 30 days.

What happens if my dog vomits after taking heartworm medicine?

If vomiting occurs within 1 hour, consult your vet—redosing may be required depending on absorption.

Can I give heartworm medicine without a test?

No. Dogs must test negative before starting prevention to avoid severe allergic reactions.

Is natural heartworm prevention effective?

No. No herbal or natural remedies are proven to prevent heartworm disease safely.

How is heartworm treated if prevention fails?

Treatment involves melarsomine injections, dog antibiotics, rest, and strict monitoring by a vet.

Does climate change affect heartworm risk?

Yes, warmer climates and longer mosquito seasons have increased year-round heartworm threats.

Can puppies get heartworm?

Yes, puppies over 6 weeks can be infected and should start prevention as early as possible.

Is flea and tick prevention enough to stop heartworm?

No. Flea and tick meds don’t prevent heartworm—dedicated heartworm prevention is required.

Leave a comment

Please note, comments must be approved before they are published