NexGard Plus vs Heartgard Plus - Which Parasite Protection Is Best?

Is your dog protected from all the parasites threatening their health — or just some of them?

When it comes to safeguarding your pet from parasitic threats, the differences between popular preventatives like NexGard Plus and Heartgard Plus go far beyond heartworm prevention. 

 

In today’s evolving climate, where fleas, ticks, hookworms, roundworms, and heartworm larvae are not only more widespread but also more resilient, choosing a single-solution product that offers broad-spectrum parasite protection has become a necessity, not a luxury.

According to recent market analysis, the global flea, tick, and heartworm products market was valued at approximately USD 6.59 billion in 2023 and is projected to grow at a CAGR of 7.4% through 2030 (Grand View Research).

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Veterinarians now emphasize year-round parasite control, particularly for dogs living in tick-prone regions or households with children or other pets. 

Medications like NexGard Plus, a combination of Afoxolaner, Moxidectin, and Pyrantel, promise complete monthly coverage. Meanwhile, Heartgard Plus, powered by Ivermectin and Pyrantel, remains a trusted heartworm preventive but may fall short when controlling external parasites like Lyme disease-carrying ticks or flea infestations.

In this guide, we’ll unpack the core differences, vet preferences, cost analysis, and user scenarios to help you determine the right fit for your dog — whether a curious puppy bounding through grass fields or a senior lounging indoors.

Overview of NexGard Plus and Heartgard Plus

Before you can make an informed decision between these two treatments, it’s crucial to understand what each product does and what it doesn’t.

What is NexGard Plus for Dogs?

NexGard Plus is a broad-spectrum parasite preventive that combines three active ingredients: 

1. Afoxolaner (for fleas and ticks), 
2. Moxidectin (for heartworm prevention), and 
3. Pyrantel (for treating intestinal worms). 

Manufactured by Boehringer Ingelheim, NexGard Plus is FDA-approved and available by prescription only.

Since its 2023 release, over 6 million doses of NexGard Plus have been distributed, signaling rapid adoption by veterinarians and dog owners alike (PR Newswire).

Designed as a chewable, once-monthly tablet, it offers protection against:

• Heartworm disease in dogs is caused by Dirofilaria immitis
• Fleas (Ctenocephalides felis)
• Ticks, including the Lone Star tick, Black-legged tick, American dog tick, and Brown dog tick
  
• Intestinal parasites like hookworms (Ancylostoma caninum) and roundworms (Toxocara canis)

With coverage that spans both internal and external parasites, NexGard Plus provides an all-in-one solution ideal for dogs exposed to the outdoors, other pets, or seasonal tick activity. It is approved for use in dogs and puppies 8 weeks or older and weighing at least 4 pounds.

What is Heartgard Plus for Dogs?

Heartgard Plus, produced by Merial (a Boehringer Ingelheim company), is a widely used heartworm preventive that also treats some intestinal parasites. Its two active ingredients — Ivermectin and Pyrantel Pamoate — work to:

• Prevent heartworm disease
  
• Treat and control hookworms and roundworms
  

Unlike NexGard Plus, Heartgard Plus does not protect against fleas or ticks, making it a narrower-spectrum product. It is best suited for dogs whose flea and tick protection is managed through other products like Frontline, Simparica, or Seresto collars.

Heartgard Plus is also a chewable tablet given monthly and is approved for dogs as young as 6 weeks old, with no minimum weight requirement — making it a popular choice for puppies and small breeds during early development stages.

What’s the difference between NexGard Plus and Heartgard Plus?

While both NexGard Plus and Heartgard Plus are trusted veterinary prescriptions for parasite prevention, they serve very different roles in your dog’s healthcare routine — especially in the breadth of protection, lifestyle fit, and preventive strategy.

1. Scope of Protection

NexGard Plus protects dogs from internal and external parasites, including fleas, ticks, heartworms, and intestinal worms. It targets fleas along with 4 major tick species in addition to heartworms and intestinal worms.

Heartgard Plus, by contrast, is a narrow-spectrum preventive effective against heartworms, hookworms, and roundworms only. It must be combined with a separate product if you want coverage for fleas and ticks.

Bottom Line: If you're looking for an all-in-one monthly chewable, NexGard Plus offers broader protection. Heartgard Plus is more minimal and best paired with another treatment.

2. Best Use Case by Environment & Lifestyle

NexGard Plus is better suited for dogs who:

• Spend time outdoors or in wooded areas
• Are frequently exposed to fleas, ticks, or other pets
• Live in tick-heavy regions like the Northeast or Midwest

Heartgard Plus is more appropriate for:

• Indoor dogs with limited tick exposure
• Puppies transitioning into parasite protocols
• Owners who already use external flea/tick preventatives like Simparica or Seresto

Bottom Line: Choose based on exposure risk. Active or outdoor dogs may benefit more from NexGard Plus.

3. Combination Flexibility vs. Convenience

If you prefer using separate treatments for different types of parasites (e.g., combining Heartgard Plus with a topical flea med), Heartgard Plus gives you that flexibility. NexGard Plus simplifies the regimen by bundling everything into one chew, which reduces the chance of missed doses.

Bottom Line: Heartgard Plus is modular; NexGard Plus is streamlined.

4. Cost-Efficiency in the Long Run

At first glance, Heartgard Plus may seem more affordable per dose. But once you factor in the added cost of a flea and tick product, total monthly costs can match or exceed those of NexGard Plus.

Bottom Line: NexGard Plus becomes more economical than Heartgard Plus when you include the cost of additional flea and tick protection.

5. Owner Preference & Routine

Some pet parents prefer the peace of mind that comes from a single monthly chew covering all threats. Others value being able to adjust treatments based on seasonal needs (e.g., only using flea meds in summer).

Bottom Line: NexGard Plus suits owners wanting a hands-off, all-in-one routine. Heartgard Plus is ideal for those who prefer to fine-tune protection.

NexGard Plus vs Heartgard Plus - Comparison Table

The main difference between NexGard Plus and Heartgard Plus is spectrum of protection. NexGard Plus treats fleas, ticks, heartworms, and intestinal worms in one chew. Heartgard Plus only treats heartworms and intestinal worms, requiring an added product for flea and tick control.

 

While both NexGard Plus and Heartgard Plus are FDA-approved and widely trusted by veterinarians, specific safety protocols and risk factors that every dog owner should be aware of before starting either medication.

Also Read: Simparica Trio vs Heartgard Plus

Is NexGard Plus or Heartgard Plus safer for dogs?

Below are the safety protocols and risk factors that every dog owner should be aware of before starting either medication.

Veterinary Protocols Before Prescribing

• Veterinarians follow a strict standard of care before initiating heartworm preventives. 
• Whether you choose NexGard Plus or Heartgard Plus, your dog must test negative for heartworm disease before starting treatment. 
• Administering these medications to a dog with an active heartworm infection could cause life-threatening complications.
• Additionally, some breeds — particularly herding breeds like Collies, Australian Shepherds, and Shelties — may carry a genetic mutation (MDR1) that affects their ability to process certain medications, especially Ivermectin, an ingredient in Heartgard Plus.
• Vets often recommend genetic testing before prescribing in such cases.

Adverse Effects & Sensitivities

Both medications are generally well-tolerated, but mild to rare side effects can occur.

• NexGard Plus: In rare cases, dogs with a history of seizures or neurological conditions may be more sensitive to Afoxolaner, a compound that acts on the nervous system of parasites.
• Your vet may recommend an alternative if your dog has known neurological triggers.
  
  
• Heartgard Plus: While uncommon, side effects can include vomiting, diarrhea, or lethargy — particularly if given on an empty stomach or if dosing errors occur.

Both medications are prescription-only, not just for legal reasons but to ensure a proper health history review before use.

Long-Term Use & Safety Assurance

One of the most common concerns pet parents have is: “Can my dog stay on this medication for years?” The answer, in most cases, is yes.

Both NexGard Plus and Heartgard Plus are designed for continuous monthly use and have demonstrated no cumulative toxicity when used long-term at prescribed doses. 

In fact, consistent use enhances effectiveness by eliminating parasite exposure windows — which are the periods when dogs are left unprotected due to skipped or delayed doses.

Pro Tip: It is recommended to visit your vet regularly to know the status of your furry friend and the dosage instructions (whether it needs to increase or decrease).

You can also set a recurring calendar reminder or use HardyPaw’s monthly subscription to ensure you never miss a dose.

Top Use Cases of Nexgard Plus & Heartgard Plus 

Now that we’ve covered the clinical side of safety and prescription protocols, let’s talk about the real-world usage of NexGard Plus and Heartgard Plus — how veterinarians actually recommend them and how pet parents apply them based on their dog’s lifestyle, age, region, and risk factors.

When the Vet Recommended NexGard Plus

Veterinarians recommend NexGard Plus for dogs exposed to: 

• wooded areas, tall grass, or tick-heavy regions.
• Live in regions where Lyme disease, Ehrlichiosis, or tick-borne anaplasmosis are prevalent
• Are prone to flea infestations, especially in warmer climates

NexGard Plus offers convenience for busy households — especially multi-dog families — where simplifying treatment routines reduces the risk of missed doses.

When Heartgard Plus is the Preferred Choice

Heartgard Plus still earns strong recommendations, particularly for:

• Dogs living indoors or in low-risk flea/tick areas
  
• Owners who already use a separate flea and tick collar or topical
  
• Puppies transitioning into full parasite coverage protocols

Some vets also prefer Heartgard Plus for sensitive breeds or when owners are looking for a more modular strategy (e.g., pairing with a Seresto collar or Simparica).

Seasonality, Regional Risk, & Rotation Strategies

Parasite exposure isn’t static — it changes based on climate, season, and geographic location. Here’s what vets typically recommend across the U.S.:

 

Source URLs:

• ScienceDirect: https://www.sciencedirect.com/science/article/pii/S0034528823002023
  
• NLM (PMC 1): https://pmc.ncbi.nlm.nih.gov/articles/PMC8163879
  
• NLM (PMC 2): https://pmc.ncbi.nlm.nih.gov/articles/PMC11658403
  
• Mordor Intelligence: https://www.mordorintelligence.com/industry-reports/heartworm-drugs-market

Parasite exposure isn’t static — it changes based on climate, season, and geographic location.

Some vets also suggest rotating medications annually (e.g., switch from NexGard Plus to Simparica Trio or Sentinel every 12–18 months) to minimize the potential for parasite resistance and maximize effectiveness.

However,always consult your vet before switching preventatives — especially if you’re combining medications. Your dog’s weight, breed, and medical history should guide every decision.

Also Read: Dental Care for Pets - Prevention Tips & Must-Have Products

How much do NexGard Plus and Heartgard Plus cost per month?

Once you’ve identified the best parasite prevention for your dog’s health and lifestyle, the next factor to weigh is the cost. 

HardyPaw offers both NexGard Plus and Heartgard Plus across all weight ranges, making it easy to compare based on your dog’s size.

NexGard Plus Monthly Pricing

Heartgard Plus Monthly Pricing

Comparative Value: One Product vs. Dual Treatment

Although Heartgard Plus has a lower per-dose cost, it only protects against heartworms and intestinal worms. Pet owners must also purchase a separate flea and tick product, such as Bravecto or a Seresto collar, which typically adds $10 to $30 per month, depending on the brand and delivery method.

For example:

• Heartgard Plus ($12.59) + Flea/Tick Topical ($15–$20) = $27.59–$32.59 per month
• NexGard Plus offers comprehensive coverage for $39.69–$44.99 depending on weight

Over time, NexGard Plus may become more cost-efficient by simplifying treatment routines and reducing the risk of missed or delayed doses.

How HardyPaw Helps Reduce Cost?

• Bundled 6-month or 12-month supplies lower per-dose pricing
• Auto-ship subscriptions ensure treatment consistency and discouns
• Periodic promotions for first-time buyers or loyal customers
• Online vet consultations help verify correct dosage and product choice

Cost-Effectiveness Summary

While NexGard Plus has a higher monthly cost, its convenience and all-in-one coverage may ultimately lead to better health outcomes and long-term savings for many dog owners.

What to Choose - NexGard Plus or Heartgard Plus?

If you're still weighing your options between NexGard Plus and Heartgard Plus, the right choice ultimately depends on:

• Your dog's environment, 
• Your treatment preferences, and 
• Your vet's guidance. 

Here's how to match the product to your situation:

Consider Your Dog’s Lifestyle and Risk Exposure

High-risk exposure dogs — those that frequent parks, wooded trails, or doggie daycare — typically benefit more from NexGard Plus, thanks to its flea and tick protection bundled with heartworm coverage.

Low-exposure indoor dogs, especially in colder climates or apartment settings, may do well with Heartgard Plus, particularly if you already have a flea and tick protocol in place.

For regional recommendations and vet preferences, refer to the Vet Recommendations section.

Think About Simplicity vs. Customization

If you value a single monthly chew and minimal complexity, NexGard Plus may suit your lifestyle better. It streamlines parasite protection and reduces the risk of missed doses.

On the other hand, Heartgard Plus gives flexibility to tailor your dog's flea and tick treatment separately. This approach works well for owners who prefer seasonally adjusting their routine or using non-chewable options like collars.

Details about routine complexity are addressed in the Key Differences and Cost Breakdown sections.

Medical History and Breed Considerations

• Herding breeds (e.g., Collies, Aussies) should be screened for the MDR1 gene mutation before starting Heartgard Plus due to sensitivity to Ivermectin.
• Dogs with a seizure history may need extra discussion with the vet before using Afoxolaner, the flea/tick ingredient in NexGard Plus.

These are not automatic contraindications but do require a conversation with your veterinarian.

More details can be found in the Effectiveness & Safety section.

Best Parasite Prevention Based on Your Dog’s Needs

Safe Medication Switch: How to Transition Between NexGard Plus and Heartgard Plus

Switching your dog from one parasite preventative to another—such as from Heartgard Plus to NexGard Plus—requires careful timing to maintain continuous protection and avoid overlapping ingredients.

1. Consult Your Veterinarian First

Before switching, speak with your vet. They’ll consider your dog's health history, lifestyle, weight, and the parasite risks in your area to recommend the safest transition schedule. This is especially important when switching between medications with different active ingredients.

2. Avoid Gaps in Coverage

Most preventatives protect for 30 days. If you're transitioning, the new product should start the day the previous one would have been due. For example:

• If your dog took Heartgard Plus on April 1, their first dose of NexGard Plus should be given on May 1.

This ensures no lapse in heartworm protection, which is critical since heartworm larvae can begin maturing within weeks of infection.

3. Avoid Overlapping Treatments

Do not give both Heartgard Plus and NexGard Plus within the same 30-day period unless explicitly directed by a veterinarian. Although both contain Pyrantel, using them together may cause excessive dosing of shared ingredients.

4. Monitor for Side Effects

After the switch, monitor your dog for any side effects, such as vomiting, lethargy, or itching. While uncommon, reactions may occur when introducing a new active ingredient like Afoxolaner (found in NexGard Plus).

5. Set Up a New Reminder Schedule

Changing products might also mean adjusting your dosing reminders. Use a calendar app, pet care tracker, or your vet’s refill service to ensure you never miss a dose of your dog’s new preventative.

Alternatives & Add-Ons: What to Pair with Heartgard Plus or Use Instead

If, after reading this guide, you're leaning toward a more flexible parasite control routine or you're managing a dog with unique health considerations, you might be wondering — what are your options beyond NexGard Plus and Heartgard Plus?

This section explores vet-approved pairings, natural support options, and what to avoid when combining medications.

Pairing Heartgard Plus with Flea & Tick Products

Heartgard Plus is highly effective for heartworm and intestinal parasites, but it doesn't protect against fleas or ticks. Fortunately, it's compatible with several leading flea and tick preventatives, which allows pet owners to customize their protection strategy.

Common pairings include:

• Simparica or Bravecto (oral chewables)
• Frontline Plus or Advantix II (topical solutions)
• Seresto Collar (odorless, 8-month duration flea/tick collar)

These pairings are often chosen based on a dog’s sensitivity, regional parasite risks, or preference for oral vs. topical application.

Important: Always consult your veterinarian before combining any treatments to avoid overlapping active ingredients or overmedication.

Can You Use NexGard Plus and Heartgard Plus Together?

• NexGard Plus already combines flea/tick and heartworm ingredients.
• Do not combine NexGard Plus with Heartgard Plus — they share ingredients like Pyrantel and Moxidectin.
  

Always check with your vet before combining medications.

Natural Flea & Tick Support (as Add-ons)

Some pet owners prefer to supplement pharmaceutical protection with natural repellents — especially in mild climates or during low-risk seasons.

Common vet-approved natural options include:

• Lemongrass or Cedarwood sprays (short-term topical deterrents)
• Apple cider vinegar sprays or rinses (discourage fleas)
• Food-grade diatomaceous earth (for bedding or outdoor areas)

While these are not substitutes for heartworm or tick-borne disease prevention, they can offer added protection when used alongside a core preventive like Heartgard Plus.

Caution: Natural doesn’t always mean safe. Avoid garlic-based sprays or essential oils that are toxic to dogs (e.g., tea tree, eucalyptus in high concentrations).

How to Decide Between NexGard Plus and Heartgard Plus?

If you want broad-spectrum, hassle-free parasite protection in one monthly chew, NexGard Plus is the superior all-in-one solution. 

But if you prefer treatment flexibility or already have a flea/tick regimen in place, Heartgard Plus remains a reliable, cost-effective heartworm preventive. The best choice is the one that fits your dog’s lifestyle and your commitment to consistent protection.

FAQs - NexGard Plus vs. Heartgard Plus

Is there a generic alternative to Heartgard Plus or NexGard Plus?
There are no FDA-approved generic versions of NexGard Plus or Heartgard Plus. Always buy from licensed veterinary pharmacies to ensure product authenticity and safety.

Can I switch from NexGard Plus to Heartgard Plus mid-year?
Yes, you can switch between products with veterinary supervision. Ensure the new medication overlaps appropriately to maintain continuous protection against parasites.

Does NexGard Plus prevent Lyme disease directly?
NexGard Plus doesn’t prevent Lyme disease itself but reduces the risk by killing ticks before they can transmit the bacteria, offering indirect but essential protection.

What is the difference between Heartgard and Heartgard Plus?

Heartgard protects only against heartworms using ivermectin. Heartgard Plus includes pyrantel, offering additional protection against roundworms and hookworms. It provides more comprehensive internal parasite coverage in a single dose.

What is the difference between NexGard and NexGard Plus?

NexGard is formulated to kill fleas and ticks only, using the active ingredient afoxolaner. NexGard Plus combines afoxolaner, moxidectin, and pyrantel, making it effective against fleas, ticks, heartworms, roundworms, and hookworms—offering broader parasite protection.

Medical References:

• https://pmc.ncbi.nlm.nih.gov/articles/PMC8163879
• https://www.mordorintelligence.com/industry-reports/heartworm-drugs-market
• https://pmc.ncbi.nlm.nih.gov/articles/PMC11658403
• https://www.drugs.com/pro/heartgard-plus.html
• https://heartgard.com/faq
• https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/14288
• https://www.sciencedirect.com/science/article/pii/S0034528823002023