Part II: Do you use flea preventatives, like Frontline, on your dog? Have you heard about the potential side effects?


My good buddy Molly posted a great comment on yesterday’s post about flea and tick preventatives, here’s an excerpt (and a picture of her dog Siegy napping with Quinn):

– I am constantly trying to find an alternative. I too have looked into the oral medications but have been hesitant to use them. Once ingested if the animal has a reaction there is not much to do other than induce vomiting. At least with a topical you can wash it off if there was an immediate reaction. But I realize the larger concern is the long term side effect of topical use like cancer or other tumors.
– I have tried Comfortis with Siegy once and he vomited a huge amount shortly after ingesting the pill. I chose not to dose him again directly after he vomited as I was directed to do by both the vet and the manufacturer of the drug. If this drug made Siegy sick once why would I immediately give him another dose? I have not tried another oral flea medication since this incident.

Here’s my response:
Thanks for the wonderful response and for sharing your experience. Poor Siegy, I’m so sorry he had such a bad reaction. Apparently this initial bought of vomiting is the most common side-effect of Comfortis. I called my vet to ask her about it and she gave the same recommendation of giving a second dose. She told me that this initial vomiting isn’t anything to worry about and that giving further doses would not cause the same reaction – seems odd, but I’ll look into this, since it goes above my level of understanding.

Lizi Angel posted a link on her blog to GreenPaws Flea and Tick Products, which I found very helpful: GreenPaws

This is what GreenPaws has written up about Comfortis, which uses the chemical Spinosad:
“Spinosad is administered to dogs in a tablet. It disrupts the nervous system function of insects, but is not neurotoxic to mammals. Its risk to humans is very slight. Veterinary reports do not indicate cause for concern, although long term studies have not been conducted. EPA classifies Spinosad as not likely to be a carcinogen. [source] Spinosad is listed on EcoWise Certified IPM Program Materials List.
Toxicity: Administered as a pill and therefore very low risk to humans. However, all pesticides should be used with caution and in consultation with a veterinarian.”

I was trying to find actual studies done on Comfortis, but haven’t yet – I’ll keep looking. There is one study that is referred to a lot and is described here:
Here’s an excerpt: “In a well-controlled US field study, which included a total of 470 dogs (330 dogs treated with Comfortis chewable tablets and 140 dogs treated with an active control), no serious adverse reactions were observed with Comfortis chewable tablets. All reactions were regarded as mild and did not result in any dog being removed from the study.” It continues on to say, “Over the 90-day study period, all observations of potential adverse reactions were recorded. Reactions that occurred at an incidence > 1% within any of the 3 months of observation are presented in the following table. The most frequently reported adverse reaction in dogs in the Comfortis chewable tablets and active control groups was vomiting. The occurrence of vomiting, most commonly within 48 hours after treatment, decreased with repeated doses of Comfortis chewable tablets.”

I was at Green Dog this morning and Christine set me up with a local (Oregon) company called Mad About Organics. The regiment required to maintain a flea-free dog with this company is a bit overwhelming, especially since the predictions are that this season with be BAD for fleas. Because Oregon doesn’t experience a good freeze like other parts of the country/world the consensus is that you have to keep up a regiment all year round.

With the flea season looming so large this year I’m considering putting Quinn on Comfortis, but until I decide I’ll be using Mad About Organics. I’ll continue researching and looking for studies on long-term usage of Comfortis along with other options, like Trifexis though and see what I find.

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7 Responses to Part II: Do you use flea preventatives, like Frontline, on your dog? Have you heard about the potential side effects?

  1. Molly P says:

    Thanks for the post Julia.

    I am still not sold on giving an oral flea medication to my pets. From my personal standpoint I just don’t feel right giving my pet something orally that makes him sick to his stomach. Giving another dose after they have vomited seems a little cruel. I am sure not all dogs experience this issue though. Also Comfortis and Trifexis are both new on the market and I just don’t think there has been enough studies on possible long term side effects of these drugs. A 90 day trial is hardly long enough in my mind. There have been other oral products that have come and seem to have gone like Sentinel and Program. Not sure why those products didn’t last. I do know that Program does not kill adult fleas, rather it breaks the life cycle by interrupting the growth pattern of larvae. Another issues is that people with cats will find that there is no oral medication available to give cats other than Program.

    I am considering using not products unless I see fleas on my pets. At which point I will make a decision. Siegy does have a sensitivity to flea bites though so of course I have to weigh that in as well.

    I will look into the Mad About Organics products. That would be wonderful if it worked but my past experience the natural products don’t usually do much. Haven’t tried this one though so may give it a try.

    Oh well. It is tough being a pet parent and making these decisions! There is really no easy answer. It is also frustrating because most of the info you find on these drugs if from the manufacturers, who of course say they are safe.

    Thanks for looking into it all.

    And cute pic of the boys. They look so peaceful.

  2. Julia Julia says:

    I hear your concerns and agree. Especially with the note that a 90 day trial doesn’t seem nearly long enough for drawing conclusive evidence. A couple folks were discussing using Sentinel on Twitter and saying that they’ve been happy with the results, but of course still no long-term evidence there. I’ll hope to find more conclusive information, but you (and Lizi) make good points regarding who’s really influencing the research on these products. Even though the FDA has stringent regulations and extensive procedures governing how to test products, oftentimes it’s the drug companies themselves who are paying the labs to do this testing. ARGH!

  3. leslie & wyatt says:

    excellent subject!
    i have always been hesitant, perhaps skeptical, about monthly medications not only for myself but my dog as well…
    wyatt has heartworm meds till november, at which point i stop until i have him tested in april before we start the monthly regimen again.
    as for ticks… i use advantix because it is a repellent… yes i know it is toxic to cats, but i don’t own any felines and my backfield is a virtual deer yard …
    again, as with the heartworm meds, i take a break in the winter months with the advantix.
    but my vet has suggested that it’s better to keep up with the meds year-round in order to keep the levels in wyatt’s system up in order for the meds to work at maximum capacity…
    it makes me ponder…
    just what is the best way to go about keeping our beloved doggies healthy?

  4. Julia Julia says:

    Hey Leslie! Great comments, and it sounds like you’ve got a pretty good set-up for Wyatt. Especially with the amount of time he spends outdoors with you and where you live it seems wise to use a stronger preventative, but I’ll keep an eye out for more info. Regrettably I really don’t know much at all about the details of these meds and am learning as I go along. As far as heartworm meds are concerned I again don’t know a lot about the research, but I am aware of how important it is to keep up the protection due to the fact that heartworm is fatal. I just looked quickly at my vet handbook and read that heartworms are spread by mosquitoes, which are obviously a huge issue in Maine. Once a dog is infected with heartworms, even with the right treatments, it can be fatal. I’m reading that the medications to kill the heartworms may work, but then the heartworms’ bodies will be carried into other parts of the dog’s body (from the heart), which can be fatal. It’s scary stuff. That’ll be another medication to look into for a future post. With fleas/ticks you have a chance of seeing them and stopping them, whereas with heartworms it seems you don’t.

    Also, Christine just posted a link about another flea treatment called ProMeris, which is being pulled off shelves from Pfeizer due to it’s causing skin disease.

  5. Dana says:

    I have been a pet owner my whole life. My last “generation” of 3 dogs I used Frontline for years until they aged and died. I didn’t realize the toxicity of these topicals until after they were deceased. One died of cancer, one “unwound” neurologically and I can’t help but wonder if long term Frontline use contributed. There are lawsuits over the topicals, Advantage, Frontline and others. I have studied this subject in depth and written an article on it. Suffering from Chronic Lyme Disease is the most disabling disease there is next to HIV. (per my Md) So having suffered Lyme, it is a MUST to keep them off my pets. There is virtually no difference if you apply a topical or feed them a (pesticide) pill. Topicals are absorbed through the skin, into the blood stream and throughout the pets body, including the nervous system and then out through the hair follicles in order to kill fleas/ticks. There is measurable residue ALL month long that is transferred to you and the children who pet them. At Greenpaws they recommend NOT sleeping w/a pet on Frontline because of the known neurotoxic effects in human. If interested, my article on this subject can be read at the link below, with many links to alternatives as well. Program seems the safest and although not a flea killer or tick killer it does break the flea cycle making the eggs not viable. Capstar (pills) bought OTC at most pet stores or vets can be given (is considered very safe) in the event of a flea infestation, killing all adult fleas within 30 minutes – 4hours. Program recommends using the 2 in conjunction as the perfect and safest way to give orals for killing fleas (Capstar) immediately and breaking the cycle (Program). I have found by reading “real world” comments of users of Comfortis at that approx 10% have side effects ranging from vomiting to seizures to death. Most who use Comfortis say it is awesome. But those who have seen side effects hate it of course. Long term use is a concern and only time will tell. Spinosad, the main ingredient in Comfortis shows to have very low toxicity in mammals and is actually a pesticide approved for organic crops! So many of us have likely ingested it ourselves. Comfortis is marketed for killing/preventing fleas only, but Pubmed abstracts (studies) are showing it also kills ticks and it is rumored they are trying to label Comfortis as a flea/tick killer. If you study Frontline or Advantage (or other topicals) the lawsuits speak for themselves and they should truly be banned. They are all toxic. Sensitive groups such as people w/MS, Fibro, Lyme Disease, etc., should not use topicals on their pets as it can intensify and prolong symptoms in human, causing numbness, vomiting, nausea and more. We are risking ourselves and our pets. So the brutal question is it necessary to risk both our pets and us? If their is a risk (and there is) it may be harsh but necessary to say, risk the pet and not yourself. These topicals are poison and many don’t work anymore anyway because fleas/ticks have adapted. More info if interested here:
    I personally can tell you, if you have contract Lyme Disease, there is NOTHING you wouldn’t do to never experience it again (study Daryl Halls ongoing battle w/Lyme and JoAnn Kerns daughter by googling, or simply visit a lyme disease forum to see the suffering). If you think ticks aren’t a problem in your area, think again, they are found in all 50 states and Lyme is nearly impossible to want to avoid it.
    Blessing to all pet owners making this very hard decision.

  6. Dana says:

    Quick addition to my post above. Excellent “table” of the least to most toxic flea/tick meds:

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