Best Dog Heartworm Prevention Medications: Top Picks & Reviews

Heartworm disease is a severe and potentially fatal condition in dogs, caused by parasitic worms (Dirofilaria immitis) that are transmitted through mosquito bites. Prevention is crucial since treatment is costly, complicated, and can pose health risks to your pet. With numerous heartworm preventatives available on the market, choosing the right one can be overwhelming. This guide provides an in-depth review of the best heartworm prevention medications, covering their effectiveness, safety, ease of use, and overall value.

Understanding Heartworm Disease and Prevention

Before diving into the best prevention options, it is essential to understand why heartworm prevention matters. When a mosquito carrying heartworm larvae bites a dog, the larvae enter the bloodstream and gradually mature into adult worms that reside in the heart and lungs. This can lead to severe respiratory issues, organ damage, and even death if left untreated.

The best way to protect your dog from heartworm disease is to administer a preventive medication consistently. Most preventatives work by killing heartworm larvae before they mature into adults, breaking the life cycle of the parasite. These medications are available in different forms, including oral tablets, topical treatments, and injections.

Top Heartworm Prevention Medications for Dogs

1. Heartgard Plus (Ivermectin/Pyrantel)

Best for: Broad-spectrum protection and ease of administration

Overview: Heartgard Plus is one of the most popular and widely trusted heartworm preventatives. It comes in a chewable form that most dogs enjoy and provides protection against heartworms as well as roundworms and hookworms.

Pros:

• Tasty beef-flavored chew that dogs readily consume

• Protects against heartworms and intestinal parasites

• Monthly dosing makes it easy to remember

Cons:

• Not effective against fleas or ticks

• Dogs with the MDR1 gene mutation (e.g., Collies) may be sensitive to ivermectin

Bottom Line: Heartgard Plus is an excellent choice for most dogs due to its broad parasite protection, ease of administration, and effectiveness.

2. Interceptor Plus (Milbemycin Oxime/Praziquantel)

Best for: Comprehensive parasite protection

Overview: Interceptor Plus is a chewable tablet that not only prevents heartworm disease but also treats and controls roundworms, hookworms, whipworms, and tapeworms.

Pros:

• Provides wider parasite protection compared to Heartgard Plus

• Suitable for puppies as young as six weeks old

• Tasty chicken-flavored chew

Cons:

• Does not protect against fleas and ticks

• May not be suitable for dogs with sensitivities to active ingredients

Bottom Line: If you want a heartworm preventative with added protection against intestinal parasites, Interceptor Plus is a great option.

3. Revolution (Selamectin)

Best for: Multi-purpose topical protection

Overview: Revolution is a topical medication that not only prevents heartworm disease but also protects against fleas, ear mites, sarcoptic mange, and some ticks.

Pros:

• Applied topically, making it a good option for dogs that refuse oral medications

• Offers additional flea and mite protection

• Safe for puppies as young as six weeks old

Cons:

• Can be messy and require drying time

• Does not provide broad tick protection

Bottom Line: Revolution is a great choice for dog owners looking for a heartworm preventative with additional protection against fleas and mites.

4. Advantage Multi (Imidacloprid/Moxidectin)

Best for: Dogs needing topical flea, tick, and heartworm protection

Overview: Advantage Multi is a topical heartworm prevention medication that also kills fleas and treats intestinal worms.

Pros:

• Provides heartworm, flea, and intestinal worm protection in one treatment

• Easy to apply once a month

Cons:

• Requires careful application to avoid licking by the dog

• Does not kill ticks

Bottom Line: If you prefer a topical medication and need additional flea control, Advantage Multi is a good choice.

5. ProHeart 6 & ProHeart 12 (Moxidectin)

Best for: Long-term heartworm prevention

Overview: ProHeart 6 and ProHeart 12 are injectable heartworm preventatives administered by a veterinarian every six or twelve months, respectively.

Pros:

• Eliminates the need for monthly dosing

• Great for owners who may forget to administer monthly medications

• Covers the full duration without gaps in protection

Cons:

• Requires a visit to the vet for administration

• Higher upfront cost compared to monthly medications

• Some dogs may experience mild side effects post-injection

Bottom Line: ProHeart injections are an excellent choice for pet owners looking for a hassle-free, long-term heartworm prevention solution.

6. Sentinel Spectrum (Milbemycin Oxime, Lufenuron, Praziquantel)

Best for: Broad-spectrum parasite protection, including flea birth control

Overview: Sentinel Spectrum is a chewable tablet that not only prevents heartworm disease but also controls flea populations by inhibiting flea egg development and treats intestinal worms.

Pros:

• Offers heartworm, flea, and intestinal worm protection

• Easy-to-administer chewable tablet

• Affordable compared to separate flea and worm treatments

Cons:

• Does not kill adult fleas (only prevents eggs from hatching)

• Must be given with food for proper absorption

Bottom Line: Sentinel Spectrum is a fantastic all-in-one option for dogs that need heartworm prevention along with flea control and deworming.

How to Choose the Right Heartworm Preventative for Your Dog

When selecting a heartworm prevention medication, consider the following factors:

1. Your Dog’s Lifestyle: If your dog is frequently exposed to fleas and ticks, a combination heartworm and flea preventative may be ideal.

2. Ease of Administration: Some dogs readily take chewable medications, while others may require a topical or injectable solution.

3. Additional Parasite Protection: Some medications also protect against fleas, ticks, and intestinal worms, providing more comprehensive protection.

4. Your Budget: Monthly chewables tend to be more budget-friendly, whereas injectable options require a higher upfront cost.

5. Veterinarian Recommendation: Your vet can help you choose the best option based on your dog’s breed, health status, and medical history.

Conclusion

Preventing heartworm disease is essential to ensuring your dog’s health and longevity. With a wide range of options available, from chewable tablets to topical applications and injectable solutions, there is a heartworm preventative that fits every dog’s needs. Whether you prioritize ease of administration, broad-spectrum parasite protection, or long-term effectiveness, the medications reviewed in this guide offer reliable and effective solutions. Consult your veterinarian to determine the best heartworm prevention medication for your furry friend and keep them safe from this dangerous disease.