Hartz Flea & Tick Remover Harms Some Cats And Dogs

If you plan on treating your dog or cat for fleas, talk to your vet and read these stories before applying Hartz. There are multiple instances where pets have responded adversely to the products, in some cases dying. Hartz agreed to remove a flea product for cats and kittens in 2006 based on similar adverse reactions, but according to the stories from angry pet owners (warning, they will make you want to hug your pet), there are still plenty of problems with current Hartz products.

Darryl wrote to us about what happened to his girlfriend’s dog:

Today I received a frantic call from my girlfriend about her dog Brutis. Brutis is a 130 pound Black Lab, more like a barrel shaped teddy bear. Brutis is also a very, very big boy. He lives in the country and in the Michigan summer, fleas tend to come around. My girlfriend noticed a flea on his tail and decided to give him a bath and apply some Hartz Flea & Tick remover according to the generic instructions.

Please do not get the impression she applied it improperly. It was sprayed no where near his face, nose, eyes, etc. He was sprayed outside to provide ventilation. 45 minutes later Brutis starts throw up violently, becoming weak with shaking and tremors. He would fade in and out of this condition. I went to the internet to find information, finding the advice to wash the dog with luke-warm water and dish soap. She thoroughly washed Brutis repeatedly to remove any of the flea & tick remover. He was still trying to vomit, merely dry heaving bile from his stomach. Sorry this is graphic.

We rushed the dog to Michigan State’s Emergency clinic which is roughly 15 miles away from their house. The dog continued to vomit in her back seat on the way to the clinic. He was very lethargic and unresponsive, not displaying his usual characteristics. It was determined that the Hartz spray was responsible for this violent reaction.

We don’t know how Brutis turned out, but we’ve asked for an update and will post it if Darryl replies.

If you’ve got a flea problem, HartzVictims.org suggests you ask your veterinarian for a suggestion, and avoid any OTC product from a retail store.

Update: Darryl sent us a status report on Brutis, along with a pic:

When we brought him in Friday night, he was extremely dehydrated and his heart rate was 180 bpm, when it should normally be between 60-100bpm. We were told that if we had not brought him in he would have died from either dehydration or heart failure.

After some great care provided by the MSU Emergency Clinic, Brutis is at home resting sound waiting for his next meal, and the one after that, and the one after that..

I still have to go through the trouble of getting them to cover the bill, but that is non-comparative to the value of having them exposed for the people that never have the satisfaction of bringing their pet home alive.

“Against Hartz”
(Photo: Getty)


Edit Your Comment

  1. laserjobs says:

    Putting chemicals on your pets seems a it crazy in the first place. There are way to many natural ways to keep fleas and ticks down.

  2. loganmo says:

    The OTC stuff doesn’t work anyways.

  3. macdude22 says:

    Dichotomous earth, God’s pet repellent. As long as you’re careful not to breath too much (It’s a physical lung irritant) this stuff works wonders. Dust your house for a day or so, vacuum, rub a bit into your pet (making sure not to ruffle up too much dust). My vet always looks at me like I’m a terrible pet owner when I don’t want to slather my cat in chemicals. Don’t bathe it and just rub it with frontline. I can buy 10 pounds of DE for the price of a dose of frontline.

  4. dogandmusiclover says:

    I’d like to reiterate the point that it’s better to get these medicines from your veterinarian, who is licensed to prescribe them. I hope Brutus will be okay.

  5. MY_BRUTIS says:

    The Hartz brand is a brand that thousands of people use to treat their animals. I am Brutis mom and I would never have used anyting that I thought would hurt him. So many people have lost or injured their pets without knowing how dangerous this stuff is! DO NOT EVER use Hatz brand anything on your animals. EVER.

  6. MY_BRUTIS says:

    On a good note, Brute is back to his old self. My big teddy bear :)

    I have never been so scared in my life. That company needs to be shut down!

  7. fireshaper says:

    Our dogs and cats had fleas on them, recently, so we decided to use Hartz on our two dogs and our cat. The dogs fared fine but the cat became jittery and had muscle spasms. After 3 baths she still couldn’t control her muscle spasms and we went to the vet who had to flush her out with fluids (which took about 5 hours and $200). She is fine ow, thanks to the vet, and we will never use Hartz again. Stay away from OTC flea medicines, always consult your vet before giving your pet any medicine.

  8. nova3930 says:

    We use frontline. Works much better and a lot safer than any OTC stuff.

    I don’t know if Hartz does but a lot of the OTC stuff has permethrin in it which can easily poison a dog or cat…

  9. dveight says:

    This is a very unfortunate story and I hope the dog gets better. Unfortunately, animals are like human, and each will have allergies like we do; some will have reactions, while others are not. Find something that will work, and stick with it, when trying anything new, make sure you watch the pet and get ready to wash them and get them to a vet if they have an extreme reaction too it.

  10. KitanaOR says:

    Not surprised. Remember how long it took for pet food companies to remove dead cats from cat food? Profit over life in the pet industry.

  11. ReidFleming says:

    Dawn dish soap…

    We rescued an emaciated kitten a few weeks ago and she was covered in fleas. She weighed less than a pound despite being about 4-5 weeks old. She probably wouldn’t have lasted another day and we at least knew that you shouldn’t apply any of these chemical insecticides to young animals.

    Some Googling showed this remedy:

    Soak cat in lukewarm water – massage in Dawn over the body – try to keep out of the eyes. The fleas that didn’t get caught in the soap will migrate up to the ‘high ground’ around the face where you can put them in a soapy bucket where they will DIE instantly. Rinse the cat thoroughly with warm water.

    We ended up getting 49 large fleas off her and now she is well on her way to recovery. As an aside, my wife decided that a weak solution of Dawn in a spray bottle might be effective against aphids and other plant-destroying bugs. It worked as well as the high-priced insecticidal soap sprays at a tiny fraction of the cost.

  12. MY_BRUTIS says:

    I am Brute’s mom and I just want to let everyone know he is okay. He is finally back to his old self-my big teddy bear :)
    I would have never used any kind of chemicals if I thought they would hurt him. Thousands of people have used this stuff and lost their pets. Please tell everyone you know to never ever use this.

  13. Sugarless says:

    I’m glad Brutus is okay, but other animals have died. I don’t use OTC flea or other medicines on my pets. Either they stay in the house (but can use the balcony) or they get flea treatments from the vet.

  14. Womblebug says:

    Our rescue always uses Frontline or Advantage, and recommend strongly to adopters that they avoid Hartz/Biospot/other “off brand” topical flea medication, for this very reason.

    You can get Frontline or Advantage from other places, either internet pet supply stores or Petco/Petsmart (they keep it locked up, so you have to ask). There have been reports of counterfeit product, though, so if you want to be 100% sure, get it from your vet. That being said, I order it from Australia (MUCH cheaper, even with shipping) and have never had a problem.

    MAKE SURE you do not use a dog product on a cat – they are different and the dog product can kill a cat.

  15. complexicated says:

    This product is AWFUL. Our cat was poisoned by this product, she was having seizures and neurological issues (spasms). We had to have her stomach filled with charcoal and her body flushed. I think the vet bill ended up being 300.00. The sad thing is the staff knew exactly what it was.. “Another Hartz Victim” they shouted when we came in… Its completely ridiculous that this product is on the market, they know it has issues. We followed the directions perfectly. A simple google on the subject will reveal countless other victims. Makes you wonder what kind of minor effects it can have on us humans as well. We no longer buy Hartz products of any kind and let everybody we know how awful there corporation is.

  16. dogandmusiclover says:

    P.S.–I didn’t read far enough. Brutus is okay. I’m glad!

  17. winstonthorne says:

    I work in a field where we sell replacement parts for (among other things), big-screen TV’s. One day while I was taking phone calls on the sales floor, a man called up to order a new bezel for a very expensive big-screen Sony (the bezel is the plastic frame around the screen). Apparently he had applied the drop-style flea control (i.e. Advantix) to his golden retriever, and the animal had shaken immediately afterward as if bothered by the drops. According to the customer, when the drops landed on the bezel, they marred the plastic, like acid. Ever since then, I’ve stuck to flea collars and regular baths for my pets.

  18. ekthesy says:

    Boric acid powder is a fantastic way to get fleas out of your house. One of my cats had fleas, and we used Frontline plus flea comb to rid him of fleas, and then put the boric acid powder all over the floors and carpets to get rid of the fleas in the house.

    40 Mule Team Borax works OK, but if you get the good stuff, straight-up boric acid it works a lot better. Just brush into carpet, let sit for half an hour and vacuum up.

    • buckinggrimace says:

      @ekthesy: I second the boric acid. My Mom and her dog lived with me for a while. It was only AFTER they moved out that I noticed a flea problem (without a dog host the fleas moved on to ME!). I sprinkled the carpets with boric acid (40 Mule) and left it on for 24 hours then vacuumed. Worked like a charm.

  19. sleze69 says:

    My fiancee is a vet tech and has seen LOTS of dogs and cats brought in with horrible reactions (siezures, unconscious, erradict heart, etc) to Hartz products. If you want to kill your pet, that is a cheap option.

    We use Frontline for our pets.

  20. badhatharry says:

    My vet explained to me that Hartz was basically like putting DDT on your dog. I know get Frontline from PetCo. I’m very glad your dog is all right.

    • RedwoodFlyer says:

      “My vet explained to me that Hartz was basically like putting DDT on your dog. I know get Frontline from PetCo. I’m very glad your dog is all right.”


      So…your dog will lay thin-shelled eggs :P?

      Our ferrets get 1/4th a vial of kitten-sized Revolution each month – does wonders for the ear mites and fleas that they pick up whenever they play with the neighbors’ cat…

  21. kittenfoo says:

    I’ve had good luck with using Frontline for the dogs and Revolution for the cats. They’re expensive, and I’m also wary of putting lots of chemicals onto my pets, but I find that with using the professional stuff during summer months, then keeping up a practice of regular vacuuming and monthly use of borax (which can be toxic in large doses, so you gotta be careful) year-round, I can keep the pests under control quite well. Those scary stories about Hartz have been around for years. I know I wrote about them in either 2004 or 2006 for the paper I worked for.

  22. tspack says:

    This problems with Hartz has been going on for years now, and they refuse to remove their toxic products, which means people keep using them and pets keep dying. My sister is a vet, and she warned me away from using anything from them (the flea and tick stuff because it’s toxic and everything else they produce because I don’t want such an unethical company to have my money).

  23. el_smurfo says:

    Most OTC flea medications contain Pyrethrin extracts which can cause lethargy, vomiting, nervous system symptoms and even death. My dog had reactions to both OTC Hartz and prescription K9 Advantix which also has a similar ingredient (burned the hair off his back, lethargic for 2 weeks after washing off the poison). Now we just stick with gentle soap and a flea comb and live with the summer itch.

    • RedwoodFlyer says:


      Wow..didn’t realize that OTC meds have Pyrethrin in it. Last time I saw that word was on a can of Raid and a puck of ant bait.

      Revolution, and the other vet-dispensed ones, don’t directly kill the bugs..they get absorbed into the blood stream, and the metabolites wind up in skin cells, and something happens, and the fleas die. My theory (IANADVM) is that and when pests chow down on the dead skin and stuff..the residual metabolite kills them like a power outage to Terri Schiavo

  24. el_smurfo says:


    The most common signs are tremors, drooling, lack of appetite, vomiting, diarrhea, incoordination, hyperactivity, disorientation, vocalization, depression, difficulty breathing, and seizures. Death is possible. Additionally in cats, may see ear flicking, paw shaking, or contractions/twitching of the skin.

  25. Fortain says:

    I’ve been told by my vet never to use ANY item by Hartz, regardless of what it is. Shampoo, OTC meds, you name it, don’t use it. They told me that they hate the fact that pet stores have to carry it, since most pets will have a severe reaction to it. I also asked at a groomer once what was the best shampoo for dogs with dry skin, they listed some off, and then almost at once 4 groomers all said, “But whatever you do, don’t use Hartz, it’s the worst thing in the world!” rather emphatically.

  26. MeOhMy says:

    When I first got my dog she had fleas so we grabbed some OTC stuff…I can’t remember if it was Hartz or not, but it might have been. It was a 3 month supply and we noticed that the day after we applied it, she would be pretty much wiped out the next day. Nothing really alarming, but our dog is normally fairly energetic and the day after the application, she would basically lay around all day only getting excited at all to go on a walk.

    I guess we got lucky that was all that happened. Our vet didn’t seem strongly against the OTC stuff, but he did indicate that the OTC mechanism essentially only kills a flea when it bites while the Advantix/Frontline treatments kill on contact.

  27. sp00nix says:

    This stuff killed my cat! Mother fuckers.

  28. Hitchcock says:

    The problem is not Hartz. Hartz just happens to be one of the best sellers, and hence has more bad experiences. The problems described can happen with ANY brand of OTC flea shampoo, powder or spray. All flea medication lists the active ingredients, there’s 3 or 4 common ones that are used by almost any anti-flea solution.

    • PinkBox says:

      @Hitchcock: The problem IS with Hartz for the very same reason. They are one of the largest manufacturers, and they refuse to take any kind of responsibility for the problems they are causing.

      If they can get away with it, of course the smaller companies are too.

      Money > Lives.

  29. PinkBox says:

    I recently had to talk my mother out of using some Hartz OTC meds for tapeworms on her new puppy.

    I really don’t understand why they’re still able to sell things that are obviously dangerous to a large percentage of animals.


  30. Anomaly69 says:

    This kind of stuff killed my cat in a pretty horrendous way. Shortly after applying this stuff to him he got a tumor on his tongue, couldn’t eat and was basically starving to death. I had to put him down. I wish I could put them through what they put my little pal through.

  31. LostAngeles says:

    Years ago, my boyfriend went to PetCo to pick some of this up and the employee told him not to because it can poison cats. He didn’t get it, but he came home asking how the hell can the product be on the market if it’s so bad?

  32. _NARC_ says:

    For what it’s worth, my Boston Terrier had the exact same reaction as the dog in the example using a generic version of that. Actually, it was not the bath, but the drop on the back of the neck version.

    After he started reacting, we washed it off and took him to the vet. But he was throwing up all day, just like the article. And this was just from a couple of drops. I can’t even imagine what a whole bath of that stuff would have done to him.

    Not sure if anyone else has mentioned it, but Frontline is FDA approved, and since we switched, he has had no reactions.

  33. cyborgsuzy says:

    hartzvictims.org is an extremely biased site, and I’m not sure I like it very much.

    Hartz has a bad reputation, (and for the record I never buy that brand for my pets), but we have no idea of this is really a “wide spread” problem or not – the people “reporting” these incidents are emotional and usually aren’t doctors. They have no idea if their pet is actually being effected by the pesticide or not, and where do they disclose if they misused the product? (The fact that there’s no other agency out there to give us an idea of the size of the problem is very annoying and a whole ‘nother issue).

    I work as a toxicologist, and I don’t know how many times I’ve spoken to people (and vets for that matter) who want to blame all their health problems on pesticides when there are plenty of other ways that they (or their pets) can get sick.

    I also can’t tell you how many times I’ve run across the sentiment that “natural” chemicals (like diatomaceous earth, boric acid or the dreaded plant extracts) are soooo much better than the sceery “synthetic” chemicals like pyrethroids.

    People, please hear me: natural does not mean safer. Coating your house and your pet in diatomaceous dust is probably much higher risk to your health than using flea drops proscribed by your vet. At least the flea products come with instructions!

    It’s also wise to keep in mind that buying cheaper flea products from another country and using them in the US is illegal, and you’re opening yourself up to buying a counterfeit product. When it comes to flea products, don’t go cheap and please FOLLOW ALL THE DIRECTIONS.

  34. synergy says:

    I always wonder at those topical flea removers. While it says that you shouldn’t apply it to eyes, nose, mouth, etc. what’s to prevent them from licking themselves?? Dogs do love to do that. Somehow the dog ingested it, possibly by licking itself, and it nearly killed him.

    • kerry says:

      @synergy: With the drops you’re supposed to apply them from the back of the head to the middle of the back, so the dog can’t lick it off. My mom uses Frontline on her dog (they spend a lot of time in Wisconsin, so she uses to keep ticks away) and I’ve seen her apply it. There’s no way the dog could lick it off. Cats, on the other hand, probably can get this stuff in their mouths (by way of licking directly or licking contaminated paws) no matter where you put it.

  35. DanGarion says:

    All this stuff is a type of poison. Hartz, Frontline, Advantage. They are all types of poison, that’s how you precent fleas. It all has to do with how you administer it. But Hartz is pretty terrible stuff from my experiences.

  36. Whiskey Tango Foxtrot says:

    That stuff is POTENT!!! My mother buys it – not to put on animals, but to spray around the foundation of her house every fall to keep spiders and ants away and it works!

  37. bangbangbonnie says:

    People should stay away from K9-Advantix, too.

    My brother tried it on his basset hound because she likes being outside and it was in the height of mosquito season. Advantix, supposedly, wards off mosquitos as well as fleas and ticks, so he thought it was a win-win situation. Shortly after (maybe an hour) he applied it in the recommended dose, she started breathing heavily, drooling excessively (she’s a dry-mouthed basset) and panting. He, of course, is worried and does a quick Internet search and, come to find out, a lot of dogs have reactions (like renal failure, death, neurological problems, hair loss, etc.) to that stuff.

    He washed it off with dishsoap (which cuts through the oil designed to keep it from rubbing off) and within half an hour she was back to her normal self.

  38. JustaConsumer says:

    It is poison. You put it on a mammal. Guess what, your kids hug and kiss the animal too. It is poison people.

  39. matchkapants says:

    My cat had a similar problem when I used some sort of popular vet prescribed medicine a few years ago. I can’t remember the brand…It was the kind where you put drops on the back of his neck. He’s OK now. At the time he was vomiting violently and I called the 1-800 number on the medicine package and the support person on the phone told me the vet had gone home for the day and would call me the next day. (?!) The vet did call back the next day, but by that time it was pointless. I will NEVER use chemicals on him again. Screw the fleas.
    On a side note, I read an article this past year that says that regular vacuuming is the best flea prevention. I upgraded my vacuum and haven’t seen a flea since.

  40. anismommy says:

    Anything OTC (veterinary) is NOT regulated by FDA. That’s why they are STILL selling these awful products…There’s no one that can make them stop! And DO NOT LISTEN to these people that are using borax or diatomaceous earth, etc! These products can come in many different variations and concetrations, and WHY(?!) would you use products NOT meant for animals-needless to say toxic- on these poor guys. I know, I know… It’s cheaper!! TOO BAD! If you can’t afford the proper preventative care, DO NOT GET A PET!!! ALWAYS CONSULT YOUR VETERINARIAN before giving your animal any form of medication, meant for animals or not… If your REALLY care for your babies, pay a little more, it will save you (and them) in the long run.
    – Liz, Licensed Veterinary Technician

  41. mizmoose says:

    My vet used to say not to use Hartz Mountain stuff because it was toxic to animals. This was in 1983.

    I never used it. No surprise that the stuff is just as toxic today as it was a zillion years ago.

  42. TysonGazelle says:

    I’m a regular reader of the consumerist and have to share my own Hartz story. I’m a foster for three kittens right now and noticed a flea on one of them a month ago. I am not exactly very wealthy and was unable to contact my rescue group at the time so decided to go to the store and get Hartz.
    This may sound unusual to you but Hartz seemed to attract the fleas to the animal.
    I wish I was making this up.
    I know this because before I applied the Hartz I gave each animal a thorough flea combing to deal with their immediate discomfort at any bites and to minimize the chance for infection/anemia. Each kitten had six or less fleas on them and the old adage goes that mutlply that by ten to establish your house’s flea population.
    I applied the Hartz and a day later combed them a second time to find twn to twenty fleas per animal who seemed to be in healthy and incredibly happy condition! It was like a flea Sandals on my poor little guys!
    Well, needless to say I consulted with my vet who gave me many a lecture for going the cheapskate route and cut me a deal for the expensive stuff for my own cats. My rescue group provided it for the fosters.
    For anyone wondering how to PROPERLY eradicate fleas from their pets, here it is.
    Bathe said pet in Dawn brand dish detergent. It will not hurt your pet, they use it on animals caught in oil slicks as well, and give the pet a good flea combing while wet. This will get rid of surface fleas and ease some of their discomfort. That is after they claw your face off. Call it therapeutic for them.
    Wait 48 hours.
    Apply Frontline that is appropriate for the age/weight/type of your pet. Read the package carefully!. Advantage is also just as good.
    Apply every month during prime flea season. (summer)
    Vacuum your home twice a week and clean all linens. This includes vacuuming couches and any upholstered for six months!
    By that time you should have broken the cycle.

    • lalaland13 says:

      @TysonGazelle: I’m glad you’re fostering kitties like that, I got one of my cats from a rescue group and another from a city shelter. But ouch, you’re right, they will claw your face off. When I first got my cat (the one on the right in my picture) and tried to bathe her to get some stuff off her rear, oh lord. Not good. I had scratch marks all over. Now I use wet wipes, which are granted, still wet, but a lot better than a tub.

      As far as flea stuff, whenever I’ve tried to go OTC, I have avoided Hartz like the plague. Once I got some since there was nothing else around, but I didn’t use it because I just had a bad feeling about it. My cats are all-indoor apartment cats, so I just try to use anything not Hartz and be careful.

  43. Vegconsumer says:

    Thank you so much for posting this! A lot of people who maybe don’t have much money think it’s all the same stuff, and are just trying to do right for their animals.

    After hearing about this a couple years ago, I refuse to give hartz ANY money. I won’t buy any of their food or toys.

  44. kryrinn says:

    For those who think Frontline’s expensive:

    It’s more expensive than Advantage, yes.

    But it’s labeled to work for fleas for 90 days. Ticks it only covers for 30 days, but if you only want flea control, just use Frontline and it’ll cost you $4-5 a month, depending on the size of your pet.

  45. lamarrn says:

    Yes, this has happened to me as well. I used the Hartz flea drops on my dogs only to have them react in a very terrifying way. My 8lb Silky Terrier began tossing and turning trying to wipe the chemical off of his back, literally for several hours. I didn’t notice the irritation initially, I thought he was only playing around. But after this behavior persistented well into the night, my boyfriend decided that it was probably a reaction to the drops and gave him a bath immediately. I’ve since learned from several vets that Hartz flea collars and products are indeed toxic and harmful for pets. I make organic pet shampoos free of toxins, however after I noticed fleas I opted for a flea specific product. I’m thrilled that my experience didn’t end up tragic and I still have my loved ones.

  46. MY_BRUTIS says:

    Thank you to everyone who showed their concern for Brutis’s health. I love him so much and everyday I am so thankful to the MSU hospital for saving his life, thankful to Darryl for being there for me, getting shit done. I was a wreck that night, there is no way I would have made it to the hospital in 1pc without him. I love you baby! Brute does too-you helped save his life!
    It makes me sick to see all these different disturbing stories. So many people have lost their pets-their best friends-to this horrible product. I really hope that my bf got to some new people by posting this. Thank you Consumerist for making it happen. Hopefully by reading this, any new pet owners will be able to prevent this from happening to there pets.
    Hatrz I know you have read this- STOP KILLING OUR ANIMALS! YOU SUCK!

  47. Rhayader says:

    I also tried using a Hartz flea medication (I don’t remember exactly which one) on my cat. We usually use Revolution, but we were out and the vet wasn’t open, so we tried the Hartz. Worst. Mistake. Ever.

    The symptoms I saw were typical of the post and comments here. Vomiting/dry heaving, muscle spasms, and strange behavior. I was worried she might die, and after reading about this, I think my concerns were justified. She has never had any issue with the Revolution, but this stuff was poison to her.

    The moral of the story: STAY AWAY FROM HARTZ!!!!

  48. EhnoEscared says:

    Thank you for posting this information. Hartz is horribly evil — they know full well that their products have been killing people’s pets for years, and they’re laughing all the way to the bank.

    The EPA’s 2006 order for Hartz to change the ingredient in its flea and tick drops for cats was (and still is) a tragic joke. The “new” ingredient is just as toxic (visit http://www.HartzVictims.org). Also, the ingredient in Hartz’s flea and tick drops for dogs is STILL phenothrin (an obsolete lawn pesticide) and dogs are dying from it every single day.

    Hartz is getting away with this because their deadly products are regulated by the EPA (unlike Frontline and Advantage, which are classified as pharmaceuticals and are regulated by the FDA).


    Please visit http://www.HartzKills.org and spread the word to everyone you know who has a pet!

  49. BlessedBella says:

    Hartz killed my Bella. The flea powder.I am on a warpath to inform the public who has Known of these products since we were children. I thought it was a trusted name. The vet said she hears about Hartz side effects and deaths often. Please do your part for awareness of these products. Bella will not be just another Hartz statistic. Blessed Be.