Flea Tick and Heartworm Prevention For Dogs (How To Choose The Best Option)

One of the biggest responsibilities of a pet owner is caring for the health and wellbeing of your pet. Part of this involves preventing common health problems before they start. In dogs, three of the most common but preventable health risks are fleas, ticks, and heartworms.

What’s the best flea, tick and heartworm prevention for dogs? The safest advice we can provide is to consult your veterinarian. Prevention options vary so much and include oral pills, topical solutions, and injections. The optimal product and plan for your dog will best be determined by your veterinarian.

It helps to know a bit more about flea, tick, and heartworm prevention for dogs before discussing options with your vet. Today, you will learn about why prevention measures are necessary, how and why they work, and the different methods and options available. Armed with the information in this article, you can have a more informed chat with your vet.

Why Do You Need to Prevent Fleas in Your Dog?

Fleas are one of the most common problems for dogs, and they can lead to health problems if contracted. 

Some conditions that fleas can cause are:

  • Flea Allergy Dermatitis: An allergic condition that results in severe skin itching and irritation. Whatever you do, do not apply calamine lotion on the areas where your dog is scratching.
  • Tapeworms: An intestinal parasite that can be spread to your dog from fleas.
  • Bacterial Infections: Fleas can spread severe bacterial infections.
  • Anemia: Fleas feed on warm-blooded animals and can cause iron deficiency anemia in animals.

Fleas are harmful by themselves, but by preventing fleas, you are also preventing other potential health problems for your dog.

How can you tell if a dog has dry skin or fleas? Have a read of this article on our blog. Maybe you’ve noticed flea poop on your dog? What does this mean?

Why Do You Need to Prevent Ticks in Your Dog?

Like fleas, ticks can transmit diseases to dogs. 

All dogs need to spend time outdoors, and if in areas with tall grass and trees, the chance of contracting ticks increases. Some health risks ticks pose to dogs are:

  • Lyme Disease: A bacterial infection spread by deer ticks that can be fatal. 
  • Anaplasmosis: Can cause bruising, lameness, or uncontrolled bleeding in your pet.
  • Ehrlichiosis: An infectious disease caused by brown dog ticks that leads to anemia, bleeding episodes, lameness, eye and neurological problems, and swollen limbs.

If your dog contracts ticks, it faces serious health risks, making prevention the best way to keep your dog happy and healthy.

Why Do You Need to Prevent Heartworms in Your Dog?

Dogs are natural hosts for heartworms, which are worms that live in the heart, lungs, and associated blood vessels of pets. 

Heartworms are spread through mosquito bites, and the symptoms are not always obvious. 

It takes at least six months to diagnose a heartworm infestation, so prevention is key.

Preventatives will not get rid of heartworms already present in a dog, so it is essential to test dogs that are more than seven months old. 

The stages of heartworm disease and the symptoms of each are…

Stage 1Includes a few mild problems, such as coughing.
Stage 2Symptoms are usually mild to moderate and include occasional coughing and obvious tiredness after mild activity.
Stage 3Symptoms become more severe and include a sickly appearance, more persistent coughing, difficulty breathing, and signs of heart failure.
Stage 4This is called Caval Syndrome. Upon reaching stage 4, it becomes life-threatening, and surgery becomes the only option.

Table 1 – stages of heartworm disease

Heartworms can affect the health and quality of life of your dog, even if they have been treated and are no longer present in your pet. 

To ensure good health and the best quality of life for your dog, preventing heartworms is a must.

Flea, Tick, and Heartworm Prevention For Dogs

How do flea, tick, and heartworm prevention work?

Flea, tick, and heartworm prevention for dogs are not the same as the treatment of the same conditions. Treatment is reserved for when your dog has already contracted a parasite, while prevention is done as an early, ongoing measure to avoid the need for treatment later on.

There are a few different products to choose from in the area of flea, tick, and heartworm prevention. 

  • Topical solutions are popular for flea and tick prevention for dogs, and they are applied to the back of your pet’s neck to kill fleas and ticks before they can transmit diseases to your dog. 
  • Collars are also commonly used to repel ticks and fleas
  • Pills
  • Injections.

Heartworm prevention is a monthly process that must be done year-round

Either pills, topical solutions, or injections are used in heartworm prevention, and they work by getting rid of the earliest stages (larvae) of heartworm parasites.

What kills fleas, ticks and heartworms?

Thanks to advancements in medicine, there are options available to prevent the three most common parasites in your dog. 

The most popular brands for flea, tick, and heartworm prevention products are:

  • Trifexis for dogs
  • Sentinel for dogs 
  • Nexgard Spectra.

While these are some of the more popular products for flea, tick, and heartworm prevention for dogs, they are by no means the only products or methods available. 

The brands we’ve mentioned are the best flea, tick, heartworm prevention for dogs but be sure to discuss these options with your vet.

Flea, tick, and heartworm prevention methods

There are multiple methods available for flea, tick, and heartworm prevention in your dog, including topical applications, oral or chewable pills, collars, and injections. 

Depending on the method of prevention, there are certain pros and cons to consider.

MethodPreventsFrequency of ApplicationProsCons
TopicalFleas, ticks, heartwormMonthlyNon-prescription, affordable, works with natural oils on pet’s skin/coatSpecific to age/weight of animals, can cause allergic reactions, less convenient
Oral TabletFleas, ticks, heartwormMonthlyUsually non-prescription, available in chewable versions, affordableFewer options for 3-in-one prevention, allergic reactions possible, specific to age/weight of animals
InjectionHeartwormYearlyYearly instead of monthly administration, effective, safeMust be done by a veterinarian, possible side effects

Table 2 – pros and cons of different prevention methods

Best flea, tick, and heartworm prevention for dogs

When choosing among brands of flea, tick, and heartworm prevention products, it helps to compare the main features of the different products that are available. 

Here is how three of the top brands compare:

TrifexisFleas, heartworm, hookworm, roundworm, whipwormChewable tabletOnce per monthOTC (over the counter)Around $120 for a 6-month supply
Nexgard SpectraFleas, ticks, mites, heartworm, hookworm, roundworm, whipworm, flea tapewormChewable tabletOnce per monthOTCAround $120 for a 6-month supply
Sentinel SpectrumFleas, heartworm, hookworm, roundworm, whipworm, tapewormChewable tabletOnce per monthPrescriptionBetween $50-80 for a 6-month supply

Table 3 – top 3 best flea, tick and heartworm preventions for dogs

One tip from me. I find buying prevention products at my local vet more expensive than buying online. You can pick up the products I’ve listed above at Chewy.com or your favorite online store that sells pet products.

Important things to note about these medications

  • Trifexis kills adult fleas before they can lay eggs on your dog. But it will not kill adult heartworms. Your dog will need to test negative for heartworm before these tablets are provided. Your vet does the test.
  • Sentinel prevents eggs developing into adult fleas but it does not kill adult fleas already on your dog. You may need to add another medication to your prevention routine.

Factors To Consider When Choosing Flea, Tick, and Heartworm Prevention Products

Aside from protecting the health of your pet, there are some specific factors that you should consider when choosing flea, tick, and heartworm prevention products. 

Depending on the geographical region where you live, your dog might be more susceptible to ticks, for example.

Here are some good guidelines to consider when choosing flea, tick, and heartworm prevention products for your dog…


If your dog has easy access to trees, forests, tall grass, and weeds, or other natural environments (especially when you enjoy hiking with your dog in National Parks), it is especially important to implement tick (and flea) prevention methods.

What kills fleas, ticks and heartworms?


Does your dog spend a lot of time outdoors, frequently visit a dog park, or have contact with other dogs? If so, you will want to be sure to use flea, tick, and heartworm prevention methods.

Health History

Allergies, digestion issues, and other health factors will determine what products will work best for your dog.

Always consult your veterinarian before choosing medicinal or preventative products for your dog. 

Why is speaking to your vet important before you buy prevention medication?

  • Your vet is local to your area. For example, they would know if your area has a problem with ticks or heartworms.
  • Your vet can perform the process to test your dog for heartworm before any preventative medication is prescribed.
  • Your vet is familiar with your dog’s medical history. For example, if your dog gets flea allergy dermatitis from fleas, then you will need a medication that kills adult fleas and not just eggs and larvae.
  • Some flea, tick, and heartworm medications like Sentinel Spectrum require a prescription from your vet.
  • You will notice that Trifexis and Sentinel Spectrum do not prevent ticks. If ticks are prevalent in your local area, your vet may recommend supplementing these two medications with a separate solution for ticks. 
  • Dogs under a certain age, usually less than 6-7 months, can be harmed by some flea, tick, and heartworm prevention products. Therefore, while it is helpful to know your options, it is vital to get expert advice from your vet when choosing prevention solutions.


Michelle loves enjoying the outdoors with her dogs. She grew in a big house near the beach with German Shepherds. Nowadays, Michelle has down-sized her dogs to poodles, proving small dogs can enjoy the outdoors too! Her dogs enjoy playing fetch, swimming, and long walks. Michelle and her dogs enjoy escaping the city limits to hike, camp, and swim.

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