The dangers of fleas and ticks to your dog’s health are scary. However, in many cases, the long term effects of commercial preventatives are terrifying.

How Preventatives Can Do Harm

The job of protecting our dogs from fleas and ticks can be a stressful one. Dog guardians are bombarded with product choices, veterinary recommendations and fears of what could happen if they don’t use flea and tick products.

Veterinarians most often recommend spot-on or oral flea and tick preventatives that must be taken on a regular basis for the rest of the dog’s life. These oral and spot-on preventatives are dangerous chemicals with severe side effects.

We must look at this with common sense and consider the possible deleterious effects this could have on our dogs’ bodies.

The problem with poisoning fleas and ticks is that you also poison the host, your dog. The theory is that your dog is a lot bigger than the insect you are targeting, so they assume a little poison won’t hurt them. But what if you are giving a little poison every single month for years of your dog’s life? The answer is we don’t know because manufacturers, such as Zoetis, have only safety tested 3 months of use.

As an emergency veterinarian with 20 years experience, my hunch is that the rising cases of cancer, immune mediated diseases, chronic illness, and decreasing lifespans must be linked to something we are doing to our dogs. Flea and tick prevention is just one of them.

“First, do no harm”.

I apologize ahead of time because I’m going to make this stressful as I briefly go over the active ingredients of common flea and tick products. I promise to give you solutions after we get this out of the way. I’ll just go over a few of the most common types.

1. Pyrethrins and Pyrethroids

Pyrethrins and pyrethroids are pesticides that interfere with the way that the nerves and the brain function.

These pesticides also have been shown to cause dizziness, headache, nausea, muscle twitching, reduced energy, and convulsions. Allergic reactions to pyrethrins have resulted in heart failure, brain damage, anemia, seizures and death.

The EPA classifies pyrethrins as likely human carcinogens.

In a study from the center of public integrity it was found that in the last five years at least 1600 pet deaths from spot-on treatments were reported to the EPA. Here is the link to the EPA website so that you can read more

Examples of pyrethrin and pyrethroid containing products on the market: Defend EXspot Treatment, Zodiac Fleatrol Spot On, K9 Advantix II, Biospot Active Spot.

2. Fipronil

Fipronil is a broad spectrum insecticide that disrupts the insect nervous system by blocking GABA-gated chloride channels and glutamate-gated chloride (GluCl) channels.

Side effects shown in individuals who have eaten fipronil reported sweating, nausea, vomiting, headache, stomach pain, dizziness, weakness, and seizures. It has been found to be contained in fat, organs, urine and feces in dogs.

It has also been shown by the EPA to cause liver and kidney toxicity, thyroid cancer, nervous system toxicity, abnormal behaviors such as whining, excessive barking, crying, decreased appetite, decreased fertility, hair loss, skin inflammation and chemical burns.

Products containing Fipronil include: Frontline®, Barricade®, Easyspot®, Effipro®, Sentry Fiproguard®, Parastar®, PetArmor®, Pronyl OTC®, Spectra Sure®, and many others

Read more about fipronil:

3. Isoxazoline Class

When initially designed and synthesized as a series of bisbenzamidine isoxazolines by Dupont Pharmaceuticals, their purpose was to act as antithrombotic agents that inhibit the activity of coagulation factor Xa, although side effects included excessive bleeding and hemolysis (Quan et al., 1999).

On September 20, 2018, the U.S. Food and Drug Administration (FDA) warned animal caregivers and veterinarians about the risk of serious neurologic events, including seizures, muscle tremors and ataxia, in dogs and cats treated with certain flea and tick medications.

The warning applies to medications in the isoxazoline class—specifically, NexGard (afoxalaner), Bravecto (fluralaner), Simparica (sarolaner) and Credelio (lotilaner).

The FDA updated their release on April 22, 2019 to include another recently-approved product in the isoxazoline class—namely, Revolution Plus (selamectin and sarolaner topical solution).

More information:

4. Imidacloprid

Imidacloprid is an insecticide that acts as an insect neurotoxin.

Lab studies have shown it to cause thyroid lesions, liver toxicity, and potential kidney, as well as lung, spleen, adrenal, brain, and gonad damage. Rats who consumed imidacloprid in their diet for three months were noted to have a reduction in weight, liver damage, reduced blood clotting, and reduced platelet numbers.

Signs of toxicity in animals are hypersensitivity, reactions in the skin, excessive salivation, lethargy, vomiting, diarrhea, muscle weakness, and ataxia.

Products containing Imidacloprid include: **Seresto Flea and Tick Collar, Advantage II, K9 Advantix II

Read more about Imidacloprid:

Natural Solutions for Fleas and Ticks

1. Helpful Habits

  • Use a flea comb to check your dog regularly, especially around areas such as in and behind ears, between toes, undercarriage, and tail base.
  • Use a lint roller or baby wipe over your dog’s coat after walks.
  • More frequent baths during warm months using natural flea and tick shampoos. Ectoparasites prefer dirty haircoats. During an infestation, use citrus Castile soap, each week, followed by a final rinse with apple cider vinegar. For this rinse, use 1 part vinegar to 10 parts water.
  • Once a week, wash all of your dog’s bedding in hot water with a natural, unscented detergent. If your dog sleeps with you, throw your own bedding in the washer once a week, too.
  • Vacuuming is a key strategy, especially against fleas. Pay extra attention to “hot spots” with less foot traffic, like behind doors and couches.
  • Use a diatomaceous earth carpet treatment or two. This helps keep fleas from multiplying.
  • Treat your yard with organic, natural deterrents.

The flea’s life cycle can be as long as several months, so you’ll need to repeat these steps if you have a flea infestation.

2. Essential Oil Collar During Walks

  • Take the collar off when indoors.

3. Natural Commercial Flea and Tick Products

4. Make Your Own Natural Deterrent Spray

Flea Free Essential Oil Blend

  • 1 ½ oz base oil such as hazelnut or sweet almond
  • 4 drops clary sage essential oil
  • 1 drop citronella essential oil
  • 7 drops peppermint essential oil
  • 3 drops lemon essential oil

Goodbye Fleas & Ticks Blend

  • 8oz water
  • 4oz apple cider vinegar
  • 10 drops Neem oil
  • 10 drops cat nip oil
  • 5 drops of lemongrass or geranium oil

If you live in a warm climate where fleas are extremely difficult to manage, then you may have to resort to a chemical commercial flea and tick product.

If you have tried everything to avoid this, then I recommend:

  • Alternating every other month with natural products
  • Giving your dog Denamarin (SAM-E) 40 mg/kg once daily during the month you use chemicals
  • Detox half-way through the warm months and again at the end
  • Do every natural recommendation to try to avoid using toxic chemicals
  • Keep your dog as healthy as possible by avoiding processed foods, over vaccination, and unnecessary medications.

Lastly, have your veterinarian do a blood test every 6 months to check your dog for tick borne illnesses.