Flea, Tick and Heartworm Preventatives

Our Veterinarian explains the differences between flea, tick and heartworm preventative treatments

Flea, Tick and Heartworm Preventatives


Dr. Barbara Gleason


There are so many products available on the market today for preventing internal and external parasites, it can be a daunting experience to select the right one for your pet. This summary will clear up any confusion and aid with your selection process.

First, let’s cover the parasites we are attempting to prevent.

On the inside:







On the outside:




Ear Mites

There is no single product that covers the whole spectrum of parasites, but there are a few combinations of products that come close. Here is a flow chart that makes it easier to decide which you would like to use:

Would you like a heartworm prevention that includes flea control?

Flea control is the expensive portion of the prevention driving up the monthly costs, but while allowing for ease of dosing for regular flea control.

If No – There are many heartworm preventions that are effective against the internal parasites that do not include flea control. These all require a prescription and include oral preventions given as a treat each month such as:

Heartgard – prevents Heartworm, roundworm, and hookworm

Centrigard – topical version of Heartgard for cats

Heartgard generics – Iverhart, Triheart, and Iverhart Plus (includes deworming for


Interceptor – Prevents heartworm, roundworm, hookworm and whipworm

Interceptor Specturm – prevents tapeworm

Injectable Prevention:

Proheart 6 – Prevents heartworm, roundworm and hookworm for 6 months

Proheart 12 – Prevents heartworm, roundworm and hookworm for 12 months

Now you need to account for flea control:

Would you like oral or topical flea control?

If you chose a heartworm prevention that does not include flea control, you will need to add another product to get the external parasite prevention. There are many options available so here’s another flow chart:

If oral, the options include:

Monthly oral prevention (all require a prescription)

Comfortis – prevents fleas

Nexgard – prevents fleas, ticks, and mites

Simparica – prevents fleas, ticks, and mites

Credilio – prevents fleas, ticks, and mites

Administer once every 3 months – requires a prescription

Bravecto – prevents fleas, ticks, and mites

If a topical flea control is preferred, you can find several over-the-counter (OTC) products that are safe for your pets.

**Beware, there are also many OTC flea control products that contain pesticides which can be toxic to your pets. It is imperative to read the active ingredients and use only the products recommended. Avoid any other product despite an attractive price tag or packaging.**

The safe OTC products include Fipronil and Imidacloprid. You can find these in name-brand products:

Frontline – prevents fleas, ticks, and lice

Advantage II – prevents fleas

Advantix (NOT safe for cats) – prevents fleas and ticks

There are also many generics of these same products available. Please read the active ingredients before purchasing.

If you are looking for a flea collar, this one is used once every 8 months:

Seresto by Bayer Pharmaceuticals – prevents fleas and ticks (beware of imposter products made with unsafe pesticides)

Topical cat flea preventions – require a prescription:

Cheristin- prevents fleas

Bravecto – prevents fleas and ticks


If Yes to heartworm preventions that include flea control (require a prescription).

Would you prefer an oral or a topical?

If oral:

Monthly products:

Trifexis – prevents heartworm, roundworm, hookworm, whipworm, and fleas

Sentinel – prevents heartworm roundworm, hookworm, whipworm, and fleas

Sentinel Spectrum – prevents heartworm roundworm, hookworm, whipworm, tapeworm, and fleas

Simparica Trio – prevents heartworm, roundworm, hookworm, whipworm, fleas, and


If topical:

Monthly products:

Revolution – prevents heartworm, roundworm, hookworm, fleas, ticks, lice, mites, and ear mites

AdvantageMulti – prevents heartworm, roundworm, hookworm, whipworm, fleas, ticks, lice, and mites


To conclude:

Although the amount of products can be bewildering, your family veterinarian will have a firm understanding of the products and be able to fit them to the needs and lifestyle of your pet. Have this discussion with your veterinarian and enjoy a parasite free life for you and your pets. Our team of veterinarians is also available 24/7 on our video telehealth service to answer any questions you have.