Top 3 Best Heartworm Medications for Dogs You Might Know

A danger lurks within our furry companions is heartworm disease. Caused by a parasite named Dirofilaria immitis lodging in the heart and lung, this condition can deal great harm to lung tissues, potentially leading to fatality. This is also a perpetual threat, as mosquitoes can transmit heartworms year-round, so prevention is essential regardless of the season. In this article we will explore 3 effective heartworm medications to keep your pup safe and healthy for years to come.

Best Heartworm Medications for Dogs
Best Heartworm Medications for Dogs

3 Types of Heartworm Medications

There are 3 main types of heartworm medications for dogs:

1. Oral

This type of heartworm medication comes in chewable tablets, often flavored to make them easier to give to your dog. The active ingredients in these medications work by disrupting the development of heartworms and may also eliminate existing intestinal parasites. Popular examples include Heartgard Plus (which focuses on heartworm, roundworm, and hookworm protection) and Simparica Trio (which offers broader protection against heartworm, fleas, ticks, roundworms, and hookworms).

Heartgard Plus

Heartgard – Trusted Defense For Dogs

How It Works

Heartgard Plus comes in a convenient chewable tablet form, making administration easy for pet owners. Its powerful formula not only prevents heartworm infection but also effectively eliminates common intestinal parasites such as roundworms and hookworms. With a proven track record of efficacy, Heartgard Plus has earned a reputation as a trusted and popular choice among dog owners seeking reliable protection against a range of harmful parasites.


Convenient chewable form, familiar and trusted choice, treats existing intestinal parasites.


Limited parasite coverage beyond heartworms and round/hookworm

Simparica Trio

simparica trio
Simparica Trio-suitable for multiple types of worms

How It Works

This chewable medication offers a multifaceted defense for dogs, protecting them against heartworms, fleas, and ticks, while also tackling roundworms and hookworms. Its comprehensive nature makes it an excellent choice for dogs encountering various parasite threats. By combining multiple protective elements into one convenient form, it provides thorough coverage and peace of mind for pet owners concerned about their dog’s health and well-being.


Powerful defense against fleas, ticks, heartworms, and common intestinal parasites.


Newer medication, consult your veterinarian for long-term safety data compared to established options.

2. Topicals

These medications come in liquid form and are applied directly to your dog’s skin, usually between the shoulder blades. The active ingredients are absorbed through the skin, targeting heartworms. Some topical medications also protect against other parasites.  A common example is Revolution, which prevents heartworm disease and controls fleas, ticks, and ear mites.


Revolution For Puppies And Kittens
Revolution- Broad-spectrum protection for dogs

How It Works

Topical application that delivers a powerful broad-spectrum defense.  This easy-to-use medication, administered monthly between the shoulder blades, shields your dog from heartworms, fleas, ticks, and ear mites.


Easy topical application, broad-spectrum defense against fleas, ticks, ear mites (rare for dog owners to consider all these together)


Not as effective for some tick species compared to oral medications.

3. Injectables

Injectable medications offer a long-acting heartworm prevention solution. This type of medication is administered by your veterinarian and contains a slow-release formula that protects your dog from heartworms for an extended period, typically 6 or 12 months. A common example is Proheart, which is available in both 6-month and 12-month options.

ProHeart 6.

ProHeart 6 – Lasting shield

How It Works

ProHeart 6 offers long-lasting protection against heartworms and eliminates certain intestinal parasites.


Less frequent dosing (every 6 months) is ideal for forgetful pet owners.


Requires a vet visit for injection, may not be suitable for all dogs due to potential breed sensitivities to Moxidectin.

Choosing the Ideal Heartworm Medication for Your Dog

As you navigate the selection process, prioritise these key considerations:


If your dog is an outdoor enthusiast, consider a longer-lasting option like an injectable medication. For dogs who spend most of their time indoors, a chewable or topical medication (e.g., Heartgard Plus, Revolution) might be perfectly adequate.

image of outdoor enthusiastic dog
Outdoor Enthusiastic Dog

Breed Sensitivities

Certain dog breeds may have genetic predispositions to sensitivities towards specific ingredients in heartworm medications. Here’s where your veterinarian’s expertise becomes crucial. Discuss your dog’s breed and any known allergies with your veterinarian. They can recommend heartworm medications with ingredients that are less likely to cause adverse reactions.

choose the right meds for your dog
Choose The Right Meds For Your Dog

Ease of Administration 

Think about the method of administration that best suits your dog’s temperament and your lifestyle.  Consider your dog’s comfort level.  For some dogs, chewable tablets might be readily accepted as a treat, while others might find topical applications less stressful

ease of administration For your dogs
Dogs’ Ease of Administration


Heartworm prevention medication is an investment in your dog’s long-term health and well-being.  While cost is a factor, consider it within the broader context of potential future veterinary expenses associated with heartworm treatment. Early detection and prevention are significantly less expensive than managing a full-blown heartworm infection.

Heartworm disease is a severe threat, but it’s preventable with consistent use of the right medication. Consulting your veterinarian is the most effective way to determine which heartworm medication is the most suitable choice for your beloved dog. They can assess your dog’s individual needs, lifestyle, and any potential risk factors to create a personalized prevention plan

cost for heartworm medication for dogs
Budget For Heartworm Medication For Dogs

Potential Side Effects

No medication is without risks. Discuss concerns about  potential side effects with your veterinarian. Be aware of your dog’s reaction after the first dose and monitor them for any signs of discomfort, such as vomiting, diarrhea, or lethargy.

Cost Comparisons 

Heartworm medications vary in price depending on the brand, type (topical, chewable, injectable), and frequency of administration. Look for deals and coupons offered by Anipetshop or your veterinarian’s clinic. Remember, factor in the cost of re-dosing if your dog struggles with taking medication or you miss a dose.

Missed Doses 

We all forget sometimes! If you miss a dose of your dog’s heartworm medication, don’t panic. Contact your veterinarian for guidance. They will advise you on the best course of action, which might involve administering a double dose or waiting until the next scheduled dose.


What is The Best Heartworm Prevention Medication for Dogs?

There isn’t a single “best” medication for all dogs. The ideal choice depends on your dog’s lifestyle, breed, budget, and ease of administration. Consulting your veterinarian is the key to finding the perfect fit.

What is The Drug of Choice for Heartworms in Dogs?

There are several effective heartworm prevention medications available, and the “drug of choice” can vary depending on individual circumstances. Popular options include Heartgard Plus, Revolution, and Simparica Trio. Your veterinarian can recommend the most appropriate medication based on your dog’s needs.

Is Simparica Trio Safer than Heartgard?

Both Simparica Trio and Heartgard Plus are effective heartworm prevention medications with good safety records when used according to the directions. However, Heartgard Plus has a longer history of use, and is a trusted choice while Simparica Trio is a newer medication.

Which is Better: Heartgard or Interceptor Plus?

Both Heartgard Plus and Interceptor Plus are excellent choices, but Heartgard Plus contains just two active ingredients, making it a good option for dogs with potential allergies to some medications

By understanding the different types of heartworm medications and consulting your veterinarian, you can choose the best option to keep your dog safe and healthy year-round. Remember, prevention is key in the fight against heartworm disease.

lily waston img

Lily Watson is an author specializing in veterinary care in Australia. With a profound passion for animal welfare and a solid foundation in veterinary science, Lily has dedicated herself to disseminating valuable knowledge and information for both pet owners and professionals in this field.