The Dangers of Commercial Flea & Tick Treatments

The pet care industry is oversaturated with toxic commercial flea and tick repellents, in the forms of “spot on” treatments, collars, powders, sprays, shampoos & pills. These products use pesticides, which are detrimental to the health of you and your loved ones. The Food & Drug Administration (FDA) and the Environmental Protection Agency (EPA) regulate these drugs due to their hazardous natures. In 2008, the EPA received more than 44,000 reports of adverse reactions to commercial flea and tick medications, including 1,600 reported pet deaths. Reactions to these treatments are the most severe in small dogs, puppies, and cats. See the table on Page 2 for more information.

Safe Alternatives to Pharmaceutical Pesticides 

  • The strongest defense against parasitic insects is the health of your pet. A pet that has a healthy, balanced diet and regular exercise is less likely to be afflicted with flea & tick infestations. A strong immune system repels pests.
  • Unpasteurized apple cider vinegar has been shown to boost pet immune systems, and can help keep bugs away. You can hide a teaspoonful in your pet’s water or food each day.
  • Consistent grooming helps control flea & tick populations. Regular flea combing makes a great addition to your at-home grooming routine.
  • Frequent vacuuming, and washing fabric items in the pet’s environment are effective for flea & tick control. Certain products like FleaVac aid in killing bugs while vacuuming.
  • Food Grade Diatomaceous Earth (DE), a powder made from the fossils of unicellular plants called “diatoms,” can be sprinkled in any place where fleas seem prevalent. It is non-toxic to humans and pets, but to insects it is lethal. Do not use “Pool Grade” DE, as it is not effective for pest control and is a known human carcinogen if ingested.
  • Herbal remedies, including the oils of Lemongrass, Neem, Thyme, Rosemary, Sage and Peppermint, can be topically applied to dogs to repel pests. Extreme caution should be used when using essential oils around cats, however. Cats do not metabolize these oils in the same way as dogs and humans; therefore, they can become dangerous if inhaled or ingested by a cat.
  • Garlic is another natural flea & tick repellent, when used in very small dosages. Caution: high doses of garlic can potentially lead to red blood cell damage and gastrointestinal problems in both dogs and cats. Most supplements formulated specifically for pets are safe. A veterinarian should be consulted if you have concerns about the health of your pet.
  • Use a teaspoon of unprocessed Brewer’s Yeast daily for cats and small dogs. A tablespoon may be given to dogs that are greater than 50 pounds. Animals that are yeast intolerant may experience allergic skin reactions. Discontinue use if this occurs.
  • At night, a bowl of warm, soapy water can be placed beneath a light source to attract and trap adult fleas. Be sure to keep the soapy water in an area that pets cannot access.


Common Flea & Tick Treatments and Their Side Effects


Active Ingredient Brand Name Adverse Effects
Fipronil Frontline, Fiproguard, PetArmor Possible human carcinogen; linked to thyroid cancer in animals; can cause organ damage and enlargement; can cause loss of appetite, lowered or increased activity, convulsions, body tremors, incoordination, labored breathing, excessive salivation, reduced fertility, decreased litter sizes, and skin issues such as inflammation, ulcerations, sloughing, burns, itching, and hair loss.
Imidacloprid Advantage Possible carcinogen; evidence of thyroid lesions in dogs; can cause damage to liver, kidneys, thyroid, heart, lungs, spleen, adrenal glands, brain, gonads; linked to increased cholesterol levels in dogs; can cause incoordination, muscle weakness, labored breathing, and an increased risk of miscarriage
Methoprene Altosid Linked to increased liver size; causes headaches, eye and throat irritation, difficulty breathing, confusion, dizziness, and nausea in humans.
Permethrin Coulston’s, Repel, Sawyer Known animal carcinogen (causes liver and lung tumors), possible human carcinogen; damages lungs and kidneys; can cause tremors, incoordination, elevated body temperatures, increased aggression, decreased fertility, and bone marrow density changes.
Pyriproxyfen Advantage, K9 Advantix Causes reduced weight gain; toxic to puppies; may be carcinogenic.
Butyl-hydroxytoluene (BHT) Common preservative Known animal carcinogen, possible human carcinogen.
Butylhydroxanisole (BHA) Common preservative Known animal carcinogen, possible human carcinogen.
Carbitol Secondary ingredient in many products as a solvent Can cause headaches, depression, nausea, vomiting, diarrhea, abdominal pain, brain lesions, lung damage, and bone marrow depression.
Amitraz Amitraz Flea Collar Classified as a carcinogen by the EPA.
Selamectin Revolution, Stronghold Can be dangerous to humans with frequent exposure according to an NIH study
Tetrachlorvinphos (TCVP) Rabon, Gardona Interferes with an essential enzyme, acetylcholinesterase, which controls messaging between nerve cells, leading to neurological disorders.

Don’t just take our word for it, though.  Click the link below to read what the NRDC (National Resources Defense Council) has to say about topical flea and tick treatments.