Choosing Flea, Tick and Heartworm Pills or Medicine for Dogs

Updated June 24, 2022
Itchy pup

Preventing debilitating diseases is much easier than treating them, which is why it's important to have your dog on flea, tick, and heartworm prevention. However, with so many choices, finding the best and safest option for your pet can be a challenge. Some medications may only cover one or two parasites, whereas other combo products may prevent and protect against fleas, ticks, and heartworms in a single pill. Stay informed about the most current options so you and your veterinarian can pick the right prevention medicine for your dog.

Flea, Tick, and Heartworm Medicine Comparison Chart

Dog owners have several choices for flea, tick, and heartworm preventives. This chart displays all the information you need to pick a prevention or combination of products for your dog, including how often they should be administered, the active ingredients, and whether they can be found over the counter or requires a prescription.

Why Are Some Dog Preventions Labeled "Plus" or "Max?"

You might wonder why some preventions are followed by the word "Plus" or "Max," whereas others are not, for example Interceptor and Interceptor Plus. Most commonly, these preventives are an identical formula with the addition of an intestinal parasiticide agent. Keep an eye out for the active ingredient pyrantel, which is effective against roundworms and hookworms, or praziquantel, which kills tapeworms. These additional ingredients will deworm your dog each month for added health protection.

Combination Flea, Tick, and Heartworm Pills

If you're hoping to find a single product that will cover fleas, ticks, and heartworms, you're in luck. Simparica Trio protects dogs against fleas, ticks, and heartworms in one pill, and it also kills hookworms and roundworms. If you prefer an all-in-one topical formula, Revolution has similar qualities, though its tick protection is limited compared to Simparica Trio. It only controls the American Dog tick, which is not the species that carries Lyme disease.

How to Choose the Best Prevention for Your Dog

When deciding on a medication or combination of medications to prevent fleas, ticks, and heartworms, several factors should be taken into account. Discuss the best choice for your pet with your veterinarian.

Disease Incidence

If you live in a region with a high incidence of heartworm infection, choosing a preventive that protects against this parasite is a must. Your veterinarian can provide you with information on the risk in your county and surrounding areas, and the American Heartworm Society (AHS) provides a map on their website with nationwide data.

However, AHS reports that heartworm-positive dogs have been diagnosed in every U.S. state as well as globally, so year-round prevention is the best course of action, regardless of your location. Different regions also have unique tick species, which can carry various tick-borne diseases, including Lyme disease or Ehrlichiosis.

Method of Administration

Most medications are available as a topical liquid you must place on your dog's skin between their shoulder blades each month, or as an oral tablet/chewable. Consider which method is most convenient and least stressful for both you and your pet. If keeping a monthly schedule may be difficult for you, you could elect for one of the longer-lasting options, including Bravecto or the Seresto collar for fleas and ticks, and the ProHeart injection for heartworm protection.


When deciding between topical or oral flea, tick, and heartworm preventions, it's important to also consider other pets and people in the house, because what you put on your dog could affect them. Children (and adults) should avoid petting the dog until the topical medication has dried on their skin. Extra precautions must be taken with feline housemates if you use a topical treatment containing permethrin or pyrethrin, as these ingredients are toxic to cats. Separate the dog and cats for 72 hours after application or choose an oral product instead.

Additional Protection

Tick prevention on a golden retriever

Some products contain ingredients that address other types of parasites in addition to fleas, ticks, and heartworms. For example, Interceptor Plus takes care of hookworms, roundworms, tapeworms, and whipworms. Other heartworm preventions like Heartgard Plus, Sentinel Spectrum, and Iverhart Max also contain deworming agents for intestinal parasites.

Similarly, some flea and tick products can kill mites or mange. In fact, many are used off-label as treatments for these little pests. If your dog is prone to mange, you may want to consider one of these options, including Advantage Multi or Revolution.

Medical History

Some medical conditions or sensitivities can affect which flea, tick, or heartworm prevention is the safest for your pet. Your veterinarian may prescribe a specific product if your dog has any of the following:

  • Use caution administering certain preventives, such as Bravecto, Credelio, or Simparica Trio to dogs with a history of seizures.
  • Any of the oral preventions can cause stomach upset in dogs, particularly those with a history of digestive issues.
  • Some dogs may not be able to take the ProHeart 6 injection, as it can cause allergic reactions.
  • Herding breeds, including Collies, Australian Shepherds, and Shetland Sheepdogs, can have a multidrug resistance mutation (MDR1), which makes them sensitive to ivermectin. However, preventions containing this ingredient carry low doses, so many experts believe these products are generally safe for dogs with MDR1, though your veterinarian may recommend using a different ingredient. The all-in-one flea, tick, and heartworm pill may not be safe for these dogs.
  • Some dogs can have a localized allergic reaction to topical medications, so you may have to switch to a chewable if your dog's skin becomes irritated.


If you're on a budget, or have several dogs to treat, cost can be a concern. Many veterinarian-recommended products are available through online pet pharmacies, such as 1-800-PetMeds or, who tend to have competitive prices. Some manufacturers also offer rebates if you buy an entire year of product or a combination of flea/tick and heartworm preventive. Finally, some veterinary offices run discounts for heartworm tests of medications during National Heartworm Awareness month, which is April.

Holistic Parasite Control

Some pet owners may prefer to go the natural route to prevent heartworm, fleas, and ticks, but be advised that there is no known "natural" preventive that has been proven to work. It's understandable to want to avoid the use of potentially harsh chemicals on your dog, but prevention products contain low doses of the active ingredients and have been thoroughly tested. Side effects or reactions are relatively rare.

Keep in mind, heartworm infection is a life-threatening condition and the treatment for heartworms can even prove to be fatal. Lyme disease and other tick or flea-borne infections will also impact your dog's quality of life and may even shorten their lifespan. Therefore, the risks of leaving your dog unprotected generally far outweigh the risks associated with using preventions. If you have concerns about any products, be sure to speak with your veterinarian.

Natural Heartworm Prevention

Although holistic heartworm options have not been tested in clinical studies, they are available for use by dog owners. Natural Pet HW Protect Herbal Formula reportedly prevents mosquito bites with herbal ingredients, such as black walnut, ginger, and wormwood. The manufacturer notes that it should be used as part of a comprehensive program to prevent mosquitos and not on its own. Always speak with your veterinarian before adding any new supplements to your pet's routine to ensure it's safe for them.

Holistic Flea and Tick Methods

Veterinarians talking with dog owner

Addressing the environment can help reduce the number of fleas, ticks, or mosquitos in your home. Try planting insect repelling herbs around the edge of your yard. Lavender, lemon grass, mint, sage, and basil plants may also repel these unwanted pests.

Another safe, natural, and biological method of ridding your yard of fleas is to introduce nematodes to the area. Entomopathogenic nematodes are safe for people and animals and come in dry form, which you simply sprinkle on the lawn, then add water. You can also use diatomaceous earth on your lawn, though it's not safe to use it directly on your pet or anything they may lick or ingest.

Choosing the Safest Flea, Tick, and Heartworm Preventative Products

Dealing with parasites like fleas, ticks, and worms may seem like an insignificant concern, but allowing them to infect your dog can lead to serious illness. Treatment for these conditions are typically emotionally and financially draining. The best way to keep your dog safe is to prevent these parasites in the first place. It can be overwhelming to select the best preventive for your pet. However, you can feel confident in your choice after reviewing all available options and discussing any concerns with your veterinarian.

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Choosing Flea, Tick and Heartworm Pills or Medicine for Dogs