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Choosing the Right Heartworm Prevention Product for Your Dogs and Cats

Heatworm Prevention Products For DogsMy earlier article went through every type of intestinal parasite that is treated by various American heartworm preventatives. But, which product treats what parasite? It is not simple! I color-coded the parasites for each product to make them easy to spot.

Oral Medications

Heartgard Plus

The original. The classic. There are now many other brands (generics) of the exact same thing. Flavorings and textures may vary, but this medication prevents roundworms and hookworms along with heartworm. Some generic names are Iverhart Plus and Tri-heart Plus. Basically, if it contains ivermectin and pyrantel, it’s a version of Heartgard Plus. Many companies are now making their own versions.

Original Heartgard was simply ivermectin, and prevented heartworms only. The plus indicates the addition of pyrantel, which treats the two intestinal worms. Nowadays, the vast majority of preventatives in this category are the “plus.” There is little manufacture of regular, containing ivermectin only, although it is out there.

Iverhart Max

Yep, Iverhart Plus is a generic for Heartgard Plus. The “Max” means it has an additional ingredient: praziquantel. This treats tapeworms. So Iverhart Max prevents roundworms, hookworms, and tapeworms, in addition to heartworm.


Instead of Ivermectin, Interceptor contains Milbemycin, which I love! It prevents heartworm, but also roundworms, hookworms, and whipworms.

Interceptor Plus

You’re realizing that all “pluses” are not created equal. Heartgard Plus and Interceptor Plus are not the same! Interceptor Plus has the addition of praziquantel, for tapeworms. So this preventative treats all four: roundworms, hookworms, whipworms, and tapeworms!


This is basically Interceptor (not Plus, just regular) with the addition of Lufeneron. So, yes, it prevents heartworm, roundworms, hookworms, and whipworms. The Lufeneron is a flea birth control. It basically stops flea eggs from hatching. No, it is not a flea killer! But, if your dog meets a flea, it might crawl around for a few days, but nothing more will become of it. You won’t get an infestation. For dogs who live in areas without a lot of fleas, but the owners don’t want to drop their guard totally, this is a great option.

Sentinel Spectrum

Why not call it Sentinel Plus? Well, there are quite a few “Pluses” out there already! Sentinel spectrum is Sentinel with the addition of you guessed it, praziquantel. So, in addition to the flea birth control, this  preventative treats all four intestinal parasites: roundworms, hookworms, whipworms, and tapeworms!


What if you like the concept of Sentinel, but want a flea KILLER, not a flea birth control? Then Trifexis might be a good choice. It has the same Milbemycin as Interceptor and Sentinel. That means it treats roundworms, hookworms, and whipworms. The addition of Spinosad means it kills fleas. If a flea bites your dog, it dies. End of story.

Topical preventatives


This is a weird one – it actually covers different parasites in dogs and cats! In dogs, it does NO intestinal parasites. Zilch. Is it all bad? No – there are good uses for it! Revolution is unique because it is a liquid that goes on the skin as opposed to an oral pill like the previous medications. Even though it does not prevent or treat any intestinal parasites, it does prevent/kill fleas, treat ear mites, and even treats sarcoptic mange! It protects against one species of tick, so I usually recommend other products for dogs needing tick protection.

In cats, Revolution is awesome! It kills fleas and ear mites, prevents heartworm and treats roundworms and hookworms!

Advantage Multi

This is another topical (liquid applied to the skin) that behaves slightly differently in dogs and cats. It does much more for dogs than Revolution. In addition to killing fleas, it treats roundworms, hookworms, and whipworms. It also treats sarcoptic mange, but is not labelled for ear mites or any tick species.

For cats, it does what Revolution does, so I love it for cats! It kills fleas and ear mites, prevents heartworm and treats roundworms and hookworms!

Injectable Preventative


This is an injection given by your veterinarian that prevents heartworm for 6 months. It does nothing else. NOTHING. It was taken off the market a decade ago, then came back with limited licensure. Only a handful of vets I know even carry it. I’m sure there is a niche of pet owners who find this approach to heartworm prevention works well, so it’s not all bad. I personally never use it – I think better is out there.

So there it is – more than you ever wanted to know about which heartworm prevention product does what! Nowadays, most veterinary clinics have their own online pharmacy. If you and your veterinarian decide on a product they do not routinely stock, you can still easily get it!

Web-DVM guest blogger Dr. Karen Louis is a practicing small animal veterinarian.  See more of her articles at her blog at

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