Are Frontline and other flea prevention products bad for dogs?

I use chemical flea-prevention products on my dog, and I feel bad about it.

When I lived in North Dakota, I never had to worry about fleas. (A benefit of brutally cold weather.)

But fleas are a year-round problem here in San Diego, so I want to start an honest discussion about fleas.

There’s a lot of talk about natural flea prevention lately, and of course that’s a good thing. But what if those options aren’t possible?

Why I use chemical flea prevention on my pets

Is Frontline bad for dogs?

My approach to flea prevention is to use the least amount of toxic chemicals as possible while keeping my pets flea free.

I use chemical flea-prevention products on my pets because:

  • Fleas are a big problem in my area.
  • I can’t use natural flea-prevention products because of allergies to the ingredients (cedarwood oil, peppermint oil, sage, thyme oil, etc.)

I typically buy flea-prevention products through 1-800-PetMeds. The company recently gave me some store credit, and my last order included Advantage for the cats and K9 Advantix for Ace.

What are the potential risks of chemical flea prevention products?

Chemical flea prevention products are made with insecticides. You know, like, toxic poisons. It’s not rocket science to figure out that these could be harmful, especially over the long term.

An active ingredients in Frontline is an insecticide called fipronil. An active ingredient in K9 Advantix is an insecticide called imidacloprid.

I’m not picking on these brands. I use them regularly on my pets. I just want pet owners to think carefully about whether these products are truly necessary and how often they should be used.

Potential side effects are listed right on the packaging. For example, Advantage and K9 Advantix list that the products could cause skin irritation or gastrointestinal issues.

I’ve never noticed these types of reactions from my pets.

Instead, I’m more concerned about the potential toll these chemicals could take on my pets over time.

While it’s impossible to avoid all toxins (they’re pretty much everywhere), I believe we should do all we can to limit what our families and our pets are exposed to. Spot-on flea treatments are just one example.

Natural flea prevention options

I love that there are so many natural options available for flea prevention, and I recommend you go that route if possible, even though it’s not an option for me.

Natural flea spray with cedar oilTopical products without the chemicals

There are monthly, topical flea prevention products without harsh chemicals such as a brand called Natural Defense. This is made with peppermint oil and other natural ingredients harmless to pets and humans but deadly to fleas and ticks, according to the company.

Natural sprays

1-800-PetMeds carries a natural anti-flea spray made with cedarwood oil and peppermint oil. The company says it’s safe to use this product in addition to spot-on treatments.

Food grade diatomaceous earth

This can be sprinkled over the pet’s bedding. It’s safe for humans and pets but kills fleas and ticks by drying them out. I’ve also sprinkled a combo of salt and baking soda into my carpets to potentially kill flea eggs. I can’t say whether it actually worked, but it didn’t hurt.

What if you have to use chemical flea prevention?

Sometimes we have no choice but to use chemical flea prevention products. If that’s the case, there are still ways we can limit the toxins our pets are exposed to overall.

For example:

  • If we have to give flea prevention and heartworm prevention, we don’t have to give them to the dog on the same day. We can spread them out. In some areas, dogs won’t even need heartworm prevention.
  • We can give our pets the minimum amount of flea prevention necessary for our area. Perhaps once every six weeks instead of every four.
  • We can rotate between natural products and chemical products, assuming the natural products are effective.
  • We can limit which vaccinations our pets receive so they only get the vaccines that are truly necessary.
  • We can use natural cleaning products in the home whenever possible.
  • We can feed our dogs a raw diet or the healthiest diet we can afford.

Now I want to hear from you.

Do you use chemical flea-prevention products?

27 thoughts on “Are Frontline and other flea prevention products bad for dogs?”

  1. I remember one year we tried to go “all-natural” with flea prevention. Unfortunately, it didn’t work. We were all tormented with fleas all summer. The fleas seem really tough here in Southern California. About a year ago, I noticed topical treatments like Frontline stopped working on the dogs. Just, pointless. My new dog has a flea allergy, so this was a big deal! He was loosing all his fur, and his skin was raw and red. We tried Comfortis and he stopped chewing himself that day! We’ve been using it ever since. I’m not sure if they’re anything in Comfortis that will harm my dog over the years, but even if it does I think it is worth it because nothing else was working and he was so miserable. I guess I’m saying it’s the lesser of two evils?

    One nice thing I’ve noticed is that if we keep the fleas under control in the dogs, our indoor cats almost never need flea treatment.

    1. Lindsay Stordahl

      I really wanted to hear how the natural products work in high-flea areas, so thanks for your input.

      I see it as choosing between the less of two evils as well. Good to hear your indoor cats don’t need to be treated. I’ve been slowly decreasing how often I put flea prevention on my cats. Maybe they won’t need it at either.

  2. we actually do use frontline on piri and he already has skin issues so it’s been a little disheartening for us to use. but we live in an area where the spring and summer months are always high alert for ticks and we even found one on our dog a couple of weeks ago. we haven’t had any issues with fleas however.

  3. Yes we use Frontline as a tick preventative. We use it every 4 weeks, but it probably should be reapplied more frequently because our dogs swim a lot. However, we only use it from say May 1 through October depending on what the dogs are doing or where they are going. A longer hunting season and warmer weather would merit using it longer. But one thing we will not compromise is that we only buy the product from our vet and use it under vet supervision. I know you may be able to buy it for a couple of dollars less online, but for us these are serious chemicals and we want to make sure the amount is correct and there is no chance the product is counterfeit or expired. Also, our vet will hear of any adverse reactions sooner than we would if there should be something like a recall.

    As ypu say, it is important to balance the benefit of the product against possible side effects.

    1. Lindsay Stordahl

      Thanks for weighing in. I actually thought of your dogs while writing this post because I know they spend so much time outdoors during the hunting season. Appreciate your thoughts!

  4. This is the first year in Alaska that they are saying there are ticks in our Great State. I’ve been doing some research and while our vet uses Frontline, I think I am going to go with K9 Advantix and the reason being is it also repels mosquitos as well. And D.O.G. is a magnet for them. However I am only going to use it during the summer and maybe into September. See what the weather is like. Ours have traveled on peoples pets is what our State Vet is saying. thank you for the idea of using natural remedies instead of chemicals. I didn’t think of them. But like you, with allergies to scents and oils, chemicals, used sparingly, might be the best way to go.

    1. Lindsay Stordahl

      Oh gosh. Sorry to hear there are now ticks to worry about for you guys. I guess I didn’t even realize they weren’t an issue before.

  5. Great post. We used Frontline on Sugar but had to stop due to skin irritation. Due to her age, we are using Natural products. It is so important for every pet parent to have the knowledge on what’s best for their pet. You’ve given lots of options. Golden Thanks for sharing. Golden Woofs

  6. We are lucky that the fleas aren’t too bad here – to hot and dry. Jack gets a batch maybe once a year and good grooming usually handles it, but thanks for the options.

  7. Ticks are so bad here, we use Frontline, but only for some of the year. Despite Frontline, Mom often finds ticks on us but it is better than any natural solution we have found. No, it is not what Mom wants to do, but it has to be done.

    1. Lindsay Stordahl

      Thanks for weighing in, Emma. It helps to know I’m not the only one who uses these products.

  8. Since we also live in San Diego – and because I’m ridiculously allergic to fleabites and have a huge fear of an infestation – we use Frontline, but I only put it on Rita every other month in the summer, and every 3 months the rest of the year. I’ve been doing it that way for years (with our other dogs as well) and we’ve never had a flea problem. I did buy some D.E. to supplement the flea killing naturally if we should get an infestation, but so far I haven’t had to use it.

    1. Lindsay Stordahl

      Thanks for that feedback, Jackie. We had quite the flea problem when we first moved here since we hadn’t realized how bad they would be! Now that we haven’t seen a flea on our pets in several months, I’m going to try to cut my pets back as well. Good to hear you’ve been successful with that.

  9. Great Post!

    I feed my dog one garlic clove (minced into his food) every other day, and you can also grate cinnamon sticks onto the dog’s food too (use the sticks, not the powder).

    The scent of garlic and cinnamon helps keep away fleas/mosquitoes. And, garlic helps with overall immunity.

    1. Lindsay Stordahl

      Hi James. I’ve heard of this as well but I don’t know how effective it is. How bad are the fleas in your area?

      1. don’t really have a flea problem here, but it is a natural deterrent for most biting bugs. it’s the scent of garlic and cinnamon that bugs don’t like.

  10. We use Frontline although I sometimes skip a month or two since I have never found a tick on Donna. That said, I recently read that some tick diseases could show no symptoms or be dormant for a while… so Donna is back on Frontline regularly again just in case 😛

    She’s never really showed a bad reaction to frontline, although she gets weirdly hyper and can’t stop running around for a bit immediately after I apply it. Not sure why – –

    I probably need more research on natural products, a lot of this stuff appear to be hearsay and not really proven whether they truly are preventative or not. So I still stick to Frontline since I am at present no well-educated on the subject yet 😉 But like you I am concerned about long term effects.

  11. I’m in Florida , so like you, I have to use chemical products part of the year. I use natural products during the winter but have to bump it up to chemical during the summer or risk infestation. I would love if something natural would work all year but nothing I have tried seems to control them during the Florida summer. So I use the chemicals because that seems the least of the two evils, chemicals or flea infestation.

  12. Hi there! I also live in Southern California and my pet-friendly community is a paradise for fleas. I have opted not to use any preventatives, as my dog is very sensitive to chemicals, and has had adverse reactions to the different treatments. I am having moderate success with the following regime:
    -I bathe my dog once per week with something called DERMagic Flea Bar. It is very mild, lathers well, and has DE in it.
    -After her bath, I comb a product called Cedarcide by Best Yet into her dry fur. It is concentrated cedar oil. This prevents new fleas from jumping on her during walks and has been very effective for me. I apply this to her fur every few days between baths.
    -I take 5 minutes to flea comb my dog every day in the evening after her last walk, just as an extra precaution.
    -My dog’s bedding is very simple and easy to wash and change out. She sleeps in a crate and her bedding is just a pillow with a pillowcase. I wash and change the pillowcase once a week, shake out the pillow (outside) and stick it in the hot dryer for 30 minutes, and quickly wipe her kennel down with non-toxic cleaner. I also vacuum thoroughly at least once per week.
    With this regime, I have been able to keep the fleas away for the most part. I find about 2-3 fleas on my pup per week during the warmest months, but it’s a quick dunk in some soapy water and they’re done.
    This may not work for everyone, but if you have a few extra minutes per day, and don’t have an existing infestation, the natural methods might help some owners avoid preventives altogether. 🙂
    *If your pup has flea allergies, I would say that preventives are best since the pros outweigh the cons in those cases.

  13. I do, but I’m not thrilled about it. I gave my mutt a dose of frontline when things finally started to heat up around here. Since then, I’ve been trying to find a solution to eliminate a chemical preventative from our home. I’ve read that vinegar diluted with water repels fleas and ticks, along with a variety of essential oils. I made a concoction of water, vinegar and peppermint oil and used it while we were traveling in the west and PNW the last two weeks. I didn’t see any ticks on my mutt, but I don’t know if the populations are that prevalent in the areas we were hiking in. We found ticks on some of the humans, but the mutt was clean. I noticed that the flies stayed away from her too. While we were gettig bit, they weren’t landing on her. Maybe it is a coincidence. The true test, though, with be taking her into the Minnesota Northwoods. If it survives that, then call me a believer. 🙂

  14. I should also note that while I was talking about ticks in my above post, the concoction is supposed to keep fleas at bay too. We will see.

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