Best Dog Heartworm Prevention: Chewable, Topical & More

Heartworm disease is a serious and potentially fatal condition affecting dogs, caused by parasitic worms transmitted through mosquito bites. Prevention is far easier and more cost-effective than treatment, making heartworm preventatives a crucial part of responsible dog ownership. With a variety of options available, choosing the best preventative for your dog can feel overwhelming. This guide explores different types of heartworm preventatives, helping you make an informed decision in consultation with your veterinarian.

Chewable Heartworm Preventatives

Chewable heartworm preventatives are often the most popular choice due to their ease of administration and palatability. These monthly tablets are flavored to make them appealing to dogs, ensuring they readily consume the medication. Key ingredients in chewable preventatives include:

• Ivermectin: A common and effective ingredient.
• Milbemycin Oxime: Offers broad-spectrum protection against heartworms and certain intestinal parasites.
• Selamectin: While primarily used in topical form, it can also be found in some chewable medications.

Popular brands include Heartgard Plus (ivermectin), Interceptor Plus (milbemycin oxime), and Trifexis (milbemycin oxime and spinosad – also protects against fleas). The choice depends on your dog’s individual needs and any other parasites you wish to target.

Topical Heartworm Preventatives

Topical heartworm preventatives are applied directly to the dog’s skin, usually between the shoulder blades to prevent licking. These medications are absorbed into the bloodstream, providing monthly protection against heartworms. Some topical formulations also offer protection against fleas, ticks, and other parasites.

Key ingredients in topical preventatives often include:

• Selamectin: A broad-spectrum parasiticide effective against heartworms, fleas, ear mites, and some ticks and worms.
• Moxidectin: A potent parasiticide used in combination with other ingredients for broader protection.

Common brands include Revolution (selamectin) and Advantage Multi (imidacloprid and moxidectin). Topical preventatives are a good option for dogs that are difficult to pill or those who require broader parasite protection. However, ensure the product is fully absorbed before allowing children or other pets to interact with the application site.

Heartworm Injections

ProHeart 6 and ProHeart 12 are injectable heartworm preventatives administered by a veterinarian. ProHeart 6 provides six months of protection, while ProHeart 12 offers a full year of coverage. These injections contain moxidectin and offer a convenient alternative to monthly oral or topical medications. This option is ideal for owners who struggle to consistently administer monthly preventatives. However, some dogs may experience injection site reactions or other adverse effects, so discuss the risks and benefits with your vet.

Choosing the Right Preventative

The best heartworm preventative for your dog depends on several factors, including:

• Age and Breed: Some breeds may be more sensitive to certain medications.
• Lifestyle: Consider exposure to mosquitoes, ticks, and other parasites.
• Existing Health Conditions: Certain medications may be contraindicated for dogs with specific health problems.
• Ease of Administration: Choose a formulation that is easy for you to administer consistently.

Always consult with your veterinarian to determine the most appropriate heartworm preventative for your dog. A heartworm test is essential before starting any preventative medication to ensure your dog is not already infected. Regular heartworm testing is also recommended, even while on preventative medication, to ensure continued protection.