7 Best Heartworm Preventatives for Dogs in 2026

Irrespective of their breed and age, all dogs are vulnerable to heartworm infection. The harmful parasites take shelter in the heart, lungs, and blood vessels of dogs and cause damage to vital organs in their bodies, which can be fatal if left untreated. However, when it comes to heartworms, it is always better to prevent them than to treat the infection they cause, as the treatment is complicated, pricey, and also painful for dogs. To help you out, we’re happy to offer this blog where we will be discussing the best heartworm preventives for dogs that will ensure the safety and well-being of your canine baby. Let’s get started.

The Best Heartworms for Dogs

 The following are the best heartworm preventives for dogs that you can opt for.

1. Heartgard Plus

Heartgard Plus is formulated for dogs and puppies from 6 weeks of age. Heartgard Plus comes in the form of beef-flavored oral chewable treatments. The remedy is designed for monthly administration and helps eliminate the tissue stage of heartworm larvae (Dirofilariaimmitis) and thus helps prevent heartworm disease. It also treats and controls three species of hookworms and two species of roundworms in dogs for a month.

Mode of Administration: Oral

Active Ingredients: Ivermectin & Pyrantel

2. Credelio Plus

Credelio Plus is an easy-to-administer chew formulated for dogs and puppies from 8 weeks of age, weighing at least 3.08 lbs. They work well to prevent heartworm (Dirofilariaimmitis) disease. The monthly treatment also covers a wide range of other internal and external parasites like fleas, ticks, roundworms, hookworms, and whipworms. It is available in five strengths and should be administered according to the dog’s weight.

Mode of Administration: Oral

Active Ingredients: Lotilaner & Milbemycin Oxime

3. Interceptor Plus

Interceptor Plus for Dogs comes in the form of an oral flavored chewable treatment and works excellently to prevent heartworm disease caused by Dirofilariaimmitis. It is suitable for dogs and puppies from 6 weeks of age, weighing at least 2 lbs. The treatment is also effective against gastrointestinal worms like roundworms, hookworms, whipworms, and tapeworms. It is available in four strengths and is required to be administered monthly according to your dog’s weight.

Mode of Administration: Oral

Active Ingredients: Milbemycin Oxime and Praziquantel

4. Nuheart Generic Heartgard

The oral formula for Nuheart Generic Heartgard for Dogs is indicated to eliminate the immature form of heartworms and prevent heartworm disease caused by Dirofilariaimmitis. The treatment is designed for monthly administration and caters to canines from 6 weeks of age.

Mode of Administration: Oral

Active Ingredients: Ivermectin

5. NexGard Spectra

NexGard Spectra for Dogs is an oral chewable formula indicated for the prevention of heartworm disease. It is designed for monthly administration and can be used in dogs and puppies from 8 weeks of age, weighing at least 3 lbs. The product also covers a range of other internal and external parasites like fleas, ticks, mange, mites, roundworms, whipworms, and hookworms. It comes in five strengths formulated to cater to dogs of different weight ranges.

Mode of Administration: Oral

Active Ingredients: Afoxolaner & Milbemycin Oxime

6. Simparica Trio

Simparica Trio for Dogs comes in the form of flavored chews and caters to dogs from 8 weeks of age, weighing at least 2.8 lbs. It is indicated for the prevention of heartworm disease caused by Dirofilariaimmitis. The treatment is also effective against roundworms, hookworms, fleas, and ticks. The monthly treatment comes in six strengths and should be administered to dogs based on their weight.

Mode of Administration: Oral

Active Ingredients: Sarolaner, Moxidectin & Pyrantel

7. Advantage Multi

Advantage Multi for Dogs is a spot-on treatment that works excellently to prevent heartworm disease caused byDirofilariaimmitis. It also treats Dirofilariaimmitis circulating microfilariae in heartworm-positive dogs. The treatment needs to be administered once a month and is effective against various other parasites like fleas, sarcoptic mange, and intestinal parasites like hookworms, roundworms, and whipworms. The treatment is suitable for dogs and puppies from 7 weeks of age, weighing at least 3 lbs. It comes in four strengths to cater to canines of different weight ranges.

Mode of Administration: Topical

Active Ingredients: Imidacloprid & Moxidectin

Frequently Asked Questions

Q1. What happens if I don’t use heartworm preventive in my dog?

If you don’t use heartworm preventive in your dog, it can get infested with heartworms that can cause damage to the heart, lungs, liver, and kidneys.

Q2. Which is a safer heartworm preventive, Heartgard or Simparica Trio?

Both Heartgard and Simparica Trio are vet-recommended heartworm preventives that work very well. However, their efficacy depends on the individual dog’s health, age, and specific needs.

Q3. Are there any particular dogs that are most susceptible to heartworm infection?

All dogs are susceptible to heartworm infection. However, factors like size, how much time they spend outdoors and pre-existing health conditions make some more vulnerable than others.

Q4. What are the safest heartworm preventives for dogs?

Some of the best heartworm preventives for dogs include Heartgard, Interceptor, NexGard Spectra, Advantage Multi and Credelio Plus.

Q5. Is round-the-year heartworm prevention essential for dogs?

Year-round heartworm prevention is essential for dogs because heartworm disease is spread by mosquitoes that can thrive in all weathers.

Ending Note

We hope that the heartworm preventives mentioned in this blog will help you keep your dog safe from heartworm infections. However, keep in mind your pooch’s age and weight before deciding on a treatment. If you’re not sure which treatment will work best for your dog, get in touch with your vet for an expert’s advice.

At CanadaVetCare, we carry all the quality heartworm preventives, including the ones mentioned in the blog, along with a wide range of other remedies at discounted prices. Check out our online store to get your hands on your preferred products.