This article kindly republished by permission from [Please note: PetArmor is also a new “generic” Frontline version]

On January 14, 2011, Sergeant’s Pet Care Products, Inc. announced it had entered into
a license agreement with Sumitomo Chemical Co., Ltd., to manufacture and sell the generic equivalent of Frontline and Frontline Plus.  These products contain the pesticide fipronil.

Here is Sergeant’s press release regarding it:


“The generic concept is one that is known and trusted by consumers for human medication and treatments. More and more, generic formulations are gaining popularity in the pet market as well,” states Caryn Stichler, vice president of marketing for Sergeant’s. “We are thrilled
to be able to deliver a trusted, veterinary-recommended product to pet owners that will be available where they shop regularly and at a lower cost than the brand-name products
currently available.”

Sergeant’s new fipronil-based products will soon be available under the names Pronyl OTC and Pronyl OTC Plus, and they will also be available under its Sentry brand as FiproGuard
and FiproGuard Plus.
For years, veterinarians have urged their clients to avoid dangerous over-the-counter flea control products, and have widely recommended using Frontline products.  In fact, Frontline
is the world’s best selling flea and tick treatment.

Despite its popularity, is Frontline really safe for pets?

Frontline is not FDA-approved. It’s registered with the EPA as a pesticide, and
it’s sold exclusively through veterinarians due to a marketing strategy.

Merial (the manufacturer of Frontline) often says, “The number of adverse events reported
for Frontline has remained consistently low since the product’s introduction in 1996.”

Merial has also intentionally misled the veterinary community and pet owners by stating
that Frontline — unlike other flea and tick treatments — is not absorbed into the body and doesn’t circulate through the bloodstream, therefore it’s very safe for pets and people.

However, this EPA memorandum from 1996 clearly states otherwise:

The EPA recently investigated pet spot-on products and found that ALL of the products, including Frontline, were linked to health issues ranging from mild skin irritation to seizures and, in rare cases, to the death of the pet.

Here are the EPA’s evaluation reports for Frontline/Frontline Plus for Dogs:

Health Canada, which collaborated with the EPA on the pet spot-on product investigation, noted that a key limitation was the under-reporting of incidents by the manufacturers.

Several people have mentioned to me that when they called Merial to report an adverse incident, they were told that Frontline does not cause serious adverse reactions!

Here’s what the American Veterinary Medical Association has to say about the risks of
spot-on flea and tick treatments (including Frontline):

Besides the risk to pets, is it safe for people to be around Frontline-treated animals?

According to the EPA’s website:

“EPA is dedicated to the protection of children risks associated from exposures to pesticides, particularly those used residentially. EPA assesses all pet pesticide treatments, including spot-on products, using a screening level approach. Our review of these products includes a dermal assessment for adults and dermal and oral exposure assessment for children based upon conservative assumptions of pet contact and pesticide transfer to the persons exposed. Inhalation assessment to pet pesticide treatments is considered on a case-by-case basis. EPA scientists estimate the amount of applied pesticide that can transfer from the animal to the child’s skin from hugging or otherwise contacting a treated animal. Based on these estimates, the EPA ensures that children are protected from exposure to pesticide treated pets.”

That sounds reassuring, but Frontline was registered (approved) before the EPA
was required to implement a new safety standard for infants and children.

Prior to registration, the EPA had serious concerns about the risks that Frontline posed to commercial pet groomers, and therefore made the registration dependent on the submission of an acceptable dermal exposure study.

Later, when the EPA assessed the risk that Frontline posed to children, instead of basing
its assessment on conservative assumptions, the EPA relied on Merial’s unpublished — and deeply flawed — dermal exposure studies, which greatly underestimated the amount of pesticide that is transferred during pet contact.

If the EPA’s risk assessment had been based on conservative assumptions, it
would have determined that Frontline poses unacceptable risks to children.

(Here’s an article regarding the EPA’s reliance on unpublished industry-backed studies:)

Here’s what the NRDC’s GreenPaws website has to say about Frontline:

“There are significant health concerns associated with fipronil but in areas
with severe tick problems, limited and careful use may be warranted.  Use
sparingly and avoid if pregnant or around young children.”

Here’s a study regarding human exposure to fipronil from Frontline-treated dogs:


“Repeated exposure to such contamination can pose human health risks.”

Here is a recent study that examined acute illnesses associated with exposure to fipronil:


“This study also found that pet-care products (Frontline) were related to more than one-third of cases and accounted for the majority of childhood cases (64%).”

Here is a presentation to California’s Scientific Guidance Panel regarding fipronil:

“Potential for continuous exposure in home.  Children may be at greater
risk.  Potential concerns for cancer, hormone disruption, and developmental neurotoxicity.”

Here’s a recent study that examined the potential for fipronil to produce developmental neurotoxicity:


“Our results suggest that fipronil is inherently a more potent disruptor of
neuronal cell development than is chlorpyrifos.”

“The actual human exposure to FPN [fipronil] is poorly explored, but, as
just one example, topical pet treatment preparations contains as much as
five orders of magnitude higher FPN concentrations than those used in our
assays; with routine “petting” transfers to human skin reach 600 ppm.”

Here’s an excellent website regarding the toxicity of fipronil:


“Research now shows that even minuscule exposure is toxic to vertebrates
including humans and pets.”

Here’s Beyond Pesticide’s fact sheet for fipronil:

Here are the NPIC’s fact sheets for fipronil:

As mentioned in the above fact sheets, fipronil is highly toxic to honey bees and
aquatic organisms.  In fact, it’s so toxic to the environment, several countries —
including China — have banned it!
Frontline and FiproGuard also contain 75-90% diethylene glycol monoethyl
ether — an industrial solvent that increases the absorption of fipronil through
the skin, and poses adverse health effects for humans and pets:

UPDATE:  On 4/20/11, FidoPharm (Velcera) announced the introduction of a line of
generic Frontline products for cats and dogs, called PetArmor and PetArmor Plus.

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  • @kittehboi Mr. Breeze


    Hi Timmy, mai pal!  I was looking at Frontline advertisement today and the packaging says to apply between the shoulder blades.  Last time I checked I could EASILY lick there.  Freaking dangerous!

    • Wally

      What are you, a giraffe?  Or the little girl in Exorcist who can spin her head?  I can lick my junk but between my shoulder blades????

    • Ls1droptopvette

      Why are you licking your pet?

      • DougDeGrave<span class="comment-author-location"> from Buena Park, CA, United States</span>

        Nothing wrong with licking the kitty, as long as it’s free of fleas.

        • TinyTimmy<span class="comment-author-location"> from Portland, OR, United States</span>

          Doug – Just like there is more than one type of tea, there is more than one type of way to fight fleas.

  • Sutanpaa

    Wow, thanks, a fantastic post! 
    I’m doing research for my cat flea website. I was going to promote this stuff as an affiliate. Not anymore! Not after reading this and a few other frontline/advantage safety articles.I wish i could say i was shocked that companies can get away with this kind of stuff but unfortunately its just another case of profit at all and any cost. 

    Again brilliant marketing used to brianwash people. (more doctors smoke camels than any other cigarette…). 

    • Anonymous

      So glad it helped you! The industry and the EPA makes it really difficult for the consumer to be educated about their decisions. That is starting to change, so little step by little step, hopefully we will get closer.

  • Iluvmurphie

    So what are the safe alternatives to frontline plus if you still need flea and tick prevention?

    • debbie

      No one answered so what are the safe alternatives to frontline plus especially this year where ticks are so bad here in the northeast.

      • Charlie

        i’m interested in a safe alternative for flea AND tick prevention also.  any recommendations?

  • ahumanesoul

    Hey really sad to read stuff like this. It starts out as a good deed, dog owners and vets trying to do the right thing, but often times like has been shown these drugs just aren’t safe long-term..
    I would like to email my vet some different articles because she has not heard Frontline is safe.. I am reading though that it IS FDA approved (not that that means much 🙁  )        can someone clear this up for me? I am reading its now FDA approved is it or is it not??

    The vets don’t purposefully want to poison dogs but I think they need to do a little research online, and this goes for pushing the whole Science Diet as well  . ..  

    sad times indeed, how will ever the dog owners of the world hear that Frontline is toxic, how can this all be changed??
    we need a superhero 🙁

    • ahumanesoul

      I’m sorry I mis-typed. My vet believes Frontline is totally safe and non-toxic, I am trying to convince her otherwise..
      Why is this so hard to fine online? Literally there is maybe 1-2 articles about Frontline toxicity I feel like I’m living underground or something 🙁

      • Ajhende

        Hi there, If you look up what front line can do to us humans, it may help your case! sorry to sound cynical but vets are a business too and it may not be in their financial best interest to  be too informed regarding the secret dangers of frontline. Personally, I believe two of my pets lives were cut shorter by it and my border collie has become  relatively lethargic  since I have been using it on him.  since I lost my adorable cat a few weeks ago, I certainly will never, ever be using it again!!

        • Anonymous

          How can you vet feel a pesticide is non-toxic? That in itself makes no sense. There is a lot of information on Frontline (check fipronil, the active ingredient). According to the EPA, in 2008 Frontline had the highest number of adverse reactions and was responsible for 65% of all reactions in children. Frontline will say they sell more than other manufacturers, but oddly, lots of manufacturers claim this while refusing to release sales numbers. You can find more on here by searching for fipronil, Pet Armor or Frontline and also by using the resource links to the right.

  • Ajhende

    Front line has serious and is potentially life threatening to pets, it should be banned globally, perhaps the manufacturer shoud try some, see what it does to them!! Why should our pets be the guinee pigs!

  • Ajhende

    ahumanesoul, Apoogies but the way I see it, vets are part of it, it’s their trade and livlihood! Look at the obsessive (anal!)  amount of times we are told to worm our animals! They are also part of the mareketing strategy too!! 

  • Momma Lou

    Ok…I really need help here…I have used Front Line for many years…never had any problems until 3 years ago…it just stopped working…I used it diligently…but gave up about 4 months ago…We have torn All the carpet out…put in wood flooring…but I need to find something to kill them off the Cats…They are suffering…Can Anyone tell Me a really effective way to treat pets and get rid of the fleas?

    • Ajhende

      Hi there Momma Lou!

      I do think they rotate, as the fleas become imune. There are more natural products out there as alternatives. Neem, from a tree sourced in India, is supposed to be effective. I have used neem for a gum infection and it exceeded any antibiotics!!  I get it from neem geni, they have an online site and  I know they sell stuff to treat pets for fleas, though not tried yet but sure will be doing!   Also there are lots of natural flea repelents, like tea tree oil, though even a couple of drops of tea tree oil is fatal to a cat, so not any good to apply to their skin but there are other alternatives but just research a bit before you use. i hope this is of some use, AJ

      • Anonymous

        There’s a section here that talks about alternatives. Neem is also sort of borderline so not on the list, but if I had to choose between neem and a chemical pesticide, I would err on the side of neem. Be sure if you go that route that you get the most “natural”/”organic” product you can find. Quality is key.

        The alternatives here are at

    • Anonymous
  • Stealawayhome

    I totally agree. I have slowly begun to see that these flea and tick products are extremely toxic to our dogs, our families and the environment. Why do our vets push them? Obviously it’s money and (I’m sorry) the lack of initiative to research these chemicals and think independently. I live in an area infested by deer ticks. I pick off my dog about the same amount of ticks as when I used Frontline. Before, the ticks seemed to eventually die but only after they were partially filled with blood, meaning long enough to transfer any bacterium they might be carrying.

  • Alex NH<span class="comment-author-location"> from Newmarket, NH, United States</span>

    Does anyone know how I can get frontline plus off of plastic? My cat always went in a cabinet after I fut it on him and he got it all over the outside of my breadmaker. How can you get frontline off of things. For the record, I don’t use it anymore.

    • TinyTimmy<span class="comment-author-location"> from Portland, OR, United States</span>

      Sadly you probably cannot. Here’s an article of a dog that got stuck to a crate from Advantage. A lot of the carriers include benzene and acetone. Often it will “melt” plastics.

      • Alex NH<span class="comment-author-location"> from Newmarket, NH, United States</span>

        Well it didn’t melt it and I’m more concerned with making sure there isn’t any fipronil on the outside of it. Does that mean Acetone is a solvent for fipronil cause I might be able to try to wipe it down with that then?

  • Guest<span class="comment-author-location"> from Pontiac, MI, United States</span>

    I’ve used Frontline on 3 dogs over the course of 15 years and I’ve never had a problem. I’m fine, my children are fine, and my pets are fine (except for the 2 that died of old age). Of course no one was allowed to touch the dog for at least 24 hours and I only used it during the warm spring/summer months since my dogs were lap dogs that just went outside a few times a day to do their business. For those who live in more rural areas that have outdoor dogs perhaps get the Lyme disease vaccine and using a good old flea collar. Not sure how much safer those would be anyways.

    • TinyTimmy<span class="comment-author-location"> from Portland, OR, United States</span>

      It’s excellent you are only using this product as needed. Good on you!

    • WT FOOK<span class="comment-author-location"> from United States</span>

      My Bassett was poisoned days after licking my beagles neck after being reassured by th vet when I called him upset he ended up in the vet er. He never fully recovered and suffered bouts of sporadic episodes for 5 years. He lived until 8 :/ but he did end up dying from his last episode. He was the most expensive free dog and my baby. The vet disagreed it was the frontline I find it highly suspect. However we never used it again and stuck to traditional flea collars never had an issue with ticks or fleas and we live in ct. Winter no collars.