Kirkland Flea And Tick Control Review

Kirkland recently released a new flea and tick control product at Costco so I prepared this review for those of you who need more information about it. Kirkland is a generic brand that makes a wide variety of products for people and also animals. Kirkland products tend to be very cheap, and this is probably why they have generated so much interest lately. I believe that when considering a generic product the consumer should first know exactly what is contained in the product and therefore determine what the “brand name” version of the product is. In this review I will reveal all ingredients contained in Kirkland flea control, the “brand name” product it really represents, it’s effectiveness, and whether or not it is safe to use.

Reviewing the active ingredients contained in Kirkland flea and tick control we find the following:

  • 30.0% Etofenprox -CAS 80844-04-01
  • 3.6% (S)-Methoprene CAS 65733-16-6
  • 5.0% Piperonyl Butoxide Technical – CAS 51-06-6 (butylcarbity (6-propyliperonyl either) and related components
  • 61.4% Other ingredients

These are to be the exact same ingredients used in “Bio Spot Defense Spot On.”

Bio Spot Defense Spot On Ingredients

It appears that Kirkland flea and tick control is just a generic version of Bio Spot Defense Spot On. Since the Kirkland product has a limited history and there are not many reviews available yet, we can look to Bio Spot Defense reviews to see if this product has been effective. The products are identical, so we can safely say that the results will be the same.

Upon a thorough investigation of pet owners’ reviews of Bio Spot Defense, I have found an overwhelming majority of negative experiences with the product. Looking at reviews just from PETCO, the general consensus is that the product does not work. To summarize users comments, they basically say that the product is “horrible, bad, it doesn’t work, and it also leaves your pet greasy.” Negative reviews from Amazon include comments like, “worse than useless, disappointing, far worse than the original, Bio Spot hurt my dog, don’t waste your money.” Although difficult, I did find two positive reviews that say the product works if you apply it correctly.

Here is a video review created by a user that shows the typical experience with Bio Spot Defense. Summary: It doesn’t work!

In regards to safety, I found numerous reviews where pet owners complaining of skin burn at the site of application, which is found for almost any topical flea and tick medication. Although there were some complaints of side effects, there were many more complaints about the ineffectiveness of the product. There is not much reason to discuss the safety of the product if it can be concluded that the product is not effective in the first place.

I have been using flea and tick meds on my dogs for a long time and I regularly research the various products on the market. I can safely say that Bio Spot Defense, and consequently Kirkland flea and tick control, are not up to standard. There is an overwhelming majority of negative feedback about Bio Spot Defense and we can expect the same in the coming months from users of Kirkland flea and tick control, which is the exact same product. (Edit: Results are in: See horrific details from users in the comments section below). I would not waste my time with this product. In the words of various pet owner reviews I encountered, “You buy cheap, you get cheap.”

Kirkland Flea And Tick Control = Bio Spot Defense Spot On

In summary, Kirkland contains the same exact formula as Bio Spot Defense Spot On. If you use Kirkland, you can expect the same results as those of Bio Spot Defense users. Kirkland has basically taken an unsuccessful, ineffective product and made a cheap, generic version of it. This reveals something about Kirkland. It basically shows us that they are out for a quick buck and obviously don’t really care about animals. Releasing a low priced product and putting it alongside Frontline Plus at Costco, they know they are going to get sales, and that is ultimately their goal. By the time the market figures out that this product doesn’t work, Kirkland will already have your money and then when sales slow down, they’ll move on to the next thing.

If Kirkland was smart, they would have released a generic version of Frontline Plus and put it up against the brand name version in Costco and other outlets. In my opinion if you are going to make a generic version of a product, at least make a generic version of an effective, proven product like Frontline Plus. Fipronil, one of the active ingredients in Frontline, is now out of patent and available for use in generic products.

Generic Frontline Plus Instead Of Kirkland?

If you are looking for a budget solution for fleas and ticks, then you may want to try the generic version of Frontline Plus, which we know works well for most pet owners. Now that Fipronil has been released from patent there are new Frontline Plus generics available. One generic that has the same ingredients as Frontline is Fiproguard.


  1. says

    I used the cat flea and tick on my 12lb. beloved Maine Coon for a period of 3months time of which the fleas became so bad that he became anemic and from then on it was down hill.
    Today he finally had to be put down and at 15 years of age had developed masses in his stomach from the tocins in this product according to my vet. He lost weight down to 6lbs., pulled out his hair in hunks, and was never my healthy sweet baby again.. I wish i had know about this before it all happened, but i did get our Costco to remove it from the shelves so no one will have to go through what i just have. Sparky suffered so badly because of this product, i feel i really let him down. Please get rid of yours, it is so bad for your animals.

  2. Erin L. Bumgarner says

    I put this on my dog the night before last, she has been throwing up, lethargic, won’t eat, won’t drink, I’m afraid she is going to die. I feel horrible for doing this to her.

  3. Dianna Gell says

    I found a kitten & used a small bit of the Kirkland product on him because he had fleas. It did nothing! I ended up going to buy a flea soap to use on him & then went online & ordered Advantage. I know that product works!!

  4. Bo says

    FWIW: I’ve been using the Kirkland brand for a few years on my 65lb and 90lb dogs. Other than the oily mess, it’s been very effective and no side effects.

  5. Marie says

    Always used Frontline for our cats & it works great ! I tried one dose of Kirkland Signature Flea & Tick Control on our 20 lb. cat & within 5 hours, he started shedding chunks if fur, within 12 hours, he was bald over the entire area where I applied the solution. I went online & found out that about 90% of the reviews were negative & most cats suffered the same adverse reaction as our cat. We went to our Costco store to complain about this product but they did not want to entertain our complain & directed us to fill up a small complaint form to drop in drop box. I called Kirkland Signature customer service (1-888-987-4110) to file a report & the rep took my information then redirected me to an outside agency that follows up complains on pet products. ANIMAL PRODUCT SAFETY SERVICE (1-888-299-2973) has a live person answering their phones to take complains 24/7. They were very nice & even had an on-call vet who advised me on how to treat & care for our cat. Call these phone numbers to voice your complains, it will hopefully make them come up with a safer product & will prevent any further injury or death to other pets.

  6. tammy says

    I used Kirkland flea drop on my 20lb dog 7 days ago and he’s been throwing up liquid yellow vomit everyday ever since! He’s also been very irritable and on day one of application he ran and hid in the bathroom behind the toilet right after. It’s very saddening to see him be this way. :(

    Also, he’s still scratching none-stop. I am tossing the rest of the box away and will put him on frontline or advantage instead next month.

    I just hope my dog will recover soon from this Kirkland flea treatment :(

  7. Susan says

    I am glad I found this site too…before I bought the Kirkland product. My animals (2 cats and 1 dog) have been using Frontline all their lives, but it seems that the fleas have developed an immunity to this product. We live in No. California and especially the last few years with this drought the fleas are horrible. I gave in and treated my old dog with Trifexis. It definitely worked on the fleas with in hours, however, after treating her with this oral product she developed an enlarged liver and ultimately had to be put down. Consequently, I am not willing to use the oral products again, and I really don’t like applying poisons either….got any suggestions?

  8. lms says

    Just found my dog’s first tick in 4 years. I also tried Kirkland and have used 4 doses. 2 doses left the classic grease. 1 dose seemed to have nothing in it, as no grease. The 4th dose last week was back to greasy. And low and behold, at 10:20 this evening, I felt a big brown bump. After watching the online video, I removed the tick. Luckily my dog showed now visible signs of illness that I can link back to the medicine, but like eveyone here, I’ll stick to the good stuff. Shame on Costco for putting small profit above an animal’s health. I doubt they will make a video on how the buyers check for safety and effectiness on the flea and tick meds…too much time flying to France to buy that special vintage.

  9. Katie says

    I have got to say I am floored. I bought two 6 count boxes of the Kirkland product when it first came out about 19 months ago. I used 11 off the 12 doses I purchased and then we moved to Alaska and had 0 problems with fleas and ticks so we just stopped using it. While I used it, it worked fantastic. It did leave my dog with 3 grease slicks on her fur where I applied the product, but they were gone in 3-4 days and they were worth it because of how amazing the product was. My dog didn’t scratch ever and we had 0 problems with it. Now we have moved to the south and my baby has fleas badly. The vets here sell frontline for $39 for each application and there is no Costco here or anywhere near here for at matter. I went to amazon to order it and my mother in law was questioning its effectiveness so I pulled. Up reviews to prove her wrong and ended up eating a whole crow! I do to know if the product changed or if I was just really lucky with the two boxes we had because our dog never had a problem with it. I told everyone I knew about it and several of them bought and used it and I never heard a bad review from them, I am so sorry about all the trouble y’all are having. My dog had no problems but now I am terrified to buy the Kirkland one again with so so so many horrible experiences by people.

  10. Carol Slater says

    We bought Kirkland Flea and Tick Control for Cats on the 21st. of Sept. 2013. We applied it to our Kitty on Sept. 22. She seemed to tolerate it and we believed it to be a good product. However we applied it for the second time on Nov. 11. We noticed that it ran down a little on one side of her neck. We attempted to wipe it off, but found the product so greasy that it did not want to wipe off. Kitty became very lethargic that day and hid under a bed until we reached in to pull her out. She seemed unable to eat. The next day was worse and she acted like she wanted to eat. She would stand over her dish and try to eat, but could not seem to chew and or swallow. She drank a little water and went back in hiding under the bed. On the seventh of Nov. Kitty was worse. She tried to lick a little off our fingers, but gave up. We added some water to her wet food and put it in the blender to see if we could get her to “drink” some food, to no avail. On the 8th, we stopped at our vets and he said to wash her with Dawn, which we did. Still no drinking or eating. The 9th was Sat. and the Vet was closed. The 10th is today and Sunday. Kitty is failing fast. The 11th will be Veterans Day and the vet will still be closed. We are hoping Kitty will live until Tues. when we can get her some real medical help.
    Please help make it known that this product is dangerous!!!!!!!!!!

  11. Randy says

    I am presently sitting up with my beagle. A couple of hours after application, she acted lethargic and a little uncoordinated. It was worsening. I washed it off and now several hours later, she is having muscle spasms. I called my vet who said no antidote. Keep her comfortable. I had used it before and it had limited effectiveness. Vet didn’t recommend it and said some dogs build up an intolerance to etofenprox. I am sick about it. It went into the trash can.

    • Jim Johnson says

      Thank you for your comment. I also have a Beagle I have been treating with the Kirkland brand Flea and Tick treatment. Several months ago she had the same symptoms and I didn’t even think about the cause of her problems… after reading your comments it now makes sense that her problem may have been from the flea treatment. The stuff is also very greasy. The dog is fine now with no lasting problems..

  12. Fiona says

    I am so mad, I hate using chemicals on my pets, but Kitty got fleas and I purchased this crap from Costco and he keeps licking and shaking his head it looks like he had a cup of grease dumped on him.

    I will complain to Costco, it may be inexpensive but i would have paid for the more expensive Frontline had they had it in stock. kitty is going to be bathed now.

  13. sharonwilliams says

    I was going to try this as fleas seem to be really bad this year , I’ve all ways use frontline or advantages but they seem to be getting amun to them, so glad I found this ,I’ve used a pill that I got from vet just cost a bet more but it’s been working.

  14. Tom De says

    I have 4 adopted indoor cats who never get fleas of ticks. However, the Vet always put the fear in me that one single infected mosquito finding its way into our house could cause heartworms in one or all of our cats. My attraction to the Kirkland Flea and Tick treatment was that it advertised killing and repelling mosquitos. The dosage was 7.2 times as much as the sample of Evolution give to us by the Vet. This left us with 4 greasy very uncomfortable cats that did not know what to do with themselves. They were constantly trying to shake it off and would hide in unusual places. This behavior went on for 3-4 days. I know cats are sensitive to anything on their fur, but I will not put our cats through this ever again. I returned the product back to Costco..

  15. winner says

    I wish I had found this site earlier. Needless to say, I am experiencing the same frustration of Kirkland medicine NOT working, guilt-ridden over watching my dog itch, and exhausted from cleaning, spraying, and washing his environment. It’s beginning to feel like a MasterCard commercial: for the $40 I saved, I got countless fleas, hours of cleaning, and a trip to the mental health provider. The experience, priceless.
    I will spend the money and buy Frontline Plus.
    Thank you all for sharing your experience, and I hope your pets are feeling better.

  16. John says

    Same result here, I applied the Costco to my cats and it seemed effective. However one of them picked up fleas so I applied the kirkland product and did not give it another thought. Things got worse so bathed her in Dawn. Three weeks go by and the fleas are out of control so I assumed I did not apply the product correctly. So I gave her a capstar pill, two Dawn baths, and reapplied the Kirkland product. The problem seemed to go away. I also did all the usual and vacumed everything thoroughly, sprayed Zodiac flea upholstery stuff, vacumed again, combed her twice daily with a flea brush and thought all was well. Today is exactly three days later and I noticed the salt ( flea eggs) when brushing her. I was thinking it was dry skin from the dawn baths- not. Found a flea in the hair on the brush. Like most who wrote in I now have to deal with this for a month.

  17. Viki says

    Should have known better. Most times, you really do get what you pay for. Have historically had great results with Advantix. Tried the Kirkland formula on our three large dogs and it was useless. Now have to wait three more weeks before we can treat them with Advantix. Just shoot me…

  18. Eddie Wendt says

    I agree with several of these postings bottom line the Kirkland brand is crap (code for it does not work). I have a large Malamute and applied it to the letter of the direction on the box. She has more fleas then ever, we were using Frontline which was working ok but not great. I thought the price was incredible for the Kirkland product, most of their products are pretty reliable. Anyway don’t waste your money on it. It does not work, it does make your dog greasy and smelly. I have had better luck with giving our dog a bath once a month with the Sergeants (Tropical Breeze) shampoo, considerably less fleas for 10 days, but they come back. Vet told me fleas eggs hatch every 3 weeks. I am going to give K-9 Advantage a try next (recommended by my neighbor). This is my first posting and that is how bad the Kirkland product is.

  19. Wendy Fairman says

    I’ve used the Kirkland brand for two months now, just put the second bikes on a couple weeks ago. My dogs are covered in fleas. We’ve treated everything from the yard to the house. I’m now gonna have to take them to the vet bc they are eating their skin off trying to kill the fleas. It doesn’t work at all. I’m sooo mad right now. Dies anyone know if I could apply frontline now or will I have to wait?

  20. James says

    Ugh…My Puggle is rubbing herself raw by her tail. I specifically went to Costco to buy….really, whatever they had for this. Its the Kirkland brand. I compared the 4 different ones with the only difference being the fluid ounce amount (heavier = more). I bought it and just got back home and came upon this site. There is not a chance I will use it on her. Off to Petco to get the real stuff. Dissapointed Costco will allow a crap product on their shelves for so long….Makes no sense

  21. Donna says

    I want to thank all for thier comments & reviews. My husband just came home with this crap. He put it on my dog. After I found this page I asked him wash it off with Dawn to make sure it all came out. Thank you again! :-)

  22. Renee says

    Just purchased this product for my cat & dog a week ago. It has been ineffective for my dog, still found a flea on her tonight. That’s when I looked for reviews. I will be returning this product tomorrow. I’m really surprised Costco still selling this product. Sounds like we got off lucky with no adverse side effects for our pets.

    Thank you for this article George!

  23. claudia says

    Don’t use this product my dog almost died. He got skin.problems and got very listless. Gave him a bath he got a little better.took him to vet on pred-antibiotics–zyrtec after 2 days he is getting better. Found out a lot of people returning the product does a pet have to die?

  24. henry says

    Thanks for your comments. I bought Kirklands flea and tick control today, but I will be returning it tomorrow.

  25. Jolynn says

    I too wish I would have read the reviews before buying this product. I thought it was a generic brand for Frontline and must admit I was quite excited about the price. I also thought it was so cute that Costco sent me a postcard a few days later (for both the dog and cat products I bought) thanking me for buying it! I’d never been sent a postcard before after buying a Kirkland brand product so yet again, I was thinking “hooray for me!”. About a week later I put it on my 80-lb lab and my 2 adults cats. I was thoroughly grossed out by the amount of product we had to put on…all down my dogs back and not just in one little spot. And on both my dog and cats it left huge greasy areas that did not go away for nearly a week. My dog didn’t seem to mind, but my cats were both thoroughly bothered. My short haired cat disappeared for a day, which he usually does when feeling ill which had me worried sick. When he came back he had a huge greasy spot that was also discolored (he’s a black cat). My medium-haired tabby cat was so bothered she rubbed herself all over the driveway until she had dread-locks. Even worse, I don’t even know if it worked…my pets didn’t have fleas, I just use it as a preventative measure. I am thoroughly disappointed in the product, and, reading through all the other reviews, I’m just glad they’re ok now! I wasted $60 on this crap and will never buy this again. I’ve been telling everyone I know NOT to buy it. I’ll be spending the money on Frontline from now on. Thanks, George, for giving me a place to vent and to let others know how horrible this stuff is.

  26. Carla says

    Ugh. I wish i would have found this BEFORE I used it. I bought mine last week at Costco and put it on my 12 week old kitten. He we very greasy and would not stop licking it so I decided to give him a bath to wash it off 2 days later since he was excessively licking it off. He now has diarrhea and can barely move. We will be taking him in the vet ASAP.

  27. Natalie says

    I’m glad that I found your review before putting on the Costco flea medication on my cats. I just got it yesterday from Costco because I saw that it is way cheaper than Frontline Plus and Revolution. I even take the product and went to talk to the pharmacist there and ask if it the same as Frontline Plus and he said it similar to it. Now that I knows that it have the same ingredients as Bio Spot, there is no way I’m putting it on my cats.

  28. Jan says

    I used the Kirkland Flea & Tick on my 10 year old, 17 lb terrier mix dog. It made him greasy, & he got a hot spot on his back. It amazed me that they wanted you to put it in three spots down the dogs back. Well that is where the dog was itching, so I chose not to put in where he could ingest any of it. I just used the first spot on his neck. I have always used Advantix. It got so expensive. I didn’t use anything for three months. Then I only used one application of the Kirkland brand and very soon after I noticed my dog started drinking water like crazy, & it got worse. I took him to the vet & spent $250 on a senior dog blood work up etc. Results were, Kidneys & liver are fine, he doesn’t have diabetes. He does seem a little lethargic, but he has always been like that. Come August 1st, I will not be putting this Kirkland on him again. It just didn’t seem right. It was only $20.00 for 6 applications. I was worried about that, but chose to try it anyway. Sure glad I decided to look up on the internet about other peoples reviews. I’m not sure if it worked for fleas, as the doggie really never has fleas because I have used something on him for the six years I have had him. He is still drinking so much extra water, but acts just like he always has for six years, so I will just keep an eye on him. I think I will go take mine back to Costco, so they can know they have another person not happy with this.

    • Jan says

      I am commenting a little more on my July 31st comment about the Kirkland Flea & Tick. I will choose to say this could just be a coincidence, as I said my dog wasn’t lethargic. Well it only took another couple weeks and he continued to drink excessive water, and out of nowhere he was just exhausted. We took him back to vet & they did a scan on his belly (it was getting so swollen from all the water) The scan showed nothing. The next day August 15th he started having seizures, August 16th, he had a serious seizure and died. It is hard to wrap my mind around it, as he is gone now and had put out $1000.00 by now. A biopsy would have cost more $$$ & it wouldn’t bring back my precious little pound puppy. He was a healthy dog before putting this stuff on him. Even the people at Costco have said it isn’t getting good reviews. R.I P ” Russo”

      • George Branson says

        I am very sorry about your loss. It makes me so sad to hear about this but hopefully people can read about your story and those others that have taken the time to share their experiences. Thank you for sharing… RIP Russo

  29. Wanda Shepley says

    The Kirkland brand is horrible. Totally did not help on my cats. Thought I’d save a few bucks—NOT! Now our have cats have another month ripoff.

  30. Shaula z says

    So I have applied Costco brand flea and tick control To two wash and dried black labs. THIS WAS FOUR DAYS AGO! I now have two greasy dogs with increased flea bites and chew marks from biting fleas on their bellies. Tomorrow is another bath to get rid of this greasy non working junk from Costco. Out comes the BORAX which I grind up in old blender and shake on my carpets. I will leave this stuff on carpet for 24 hours or longer (HAVE BRUSHED IT INTO CARPET too) and it Kills ffleas, their eggs, etc. Then I vacuum it all up. This treatment lasts a long time…….How did I learn this? Fleabusters used Borax when I hired them to do thisa long time ago. It works……forget Costco and their money making USELESS PRODUCT!

    • George Branson says

      We’re right there with you. Sorry you had to go through that. You”re 100% justified. Thanks for the tip about the BORAX, sometimes we just need to go back to the old school. :)

  31. Rich T says

    Thank you Mr. Branson for your site. I, too, recently purchased the Kirkland product. I had just used the last of the Frontline Plus doses, and wanted a re-supply in my cabinet for 30 days from now. I noticed that the product ingredients were very different from those in Frontline Plus, and decided to do my homework upon getting home. You did my homework for me, and I thank you for that. I hope the generic products that you linked (with the 9.8% Fipronil and 8.8% (S)-methoprene) are safe and effective. I found the Frontline products exorbitantly priced. But effective, too. I will not be using Kirkland’s BioSpot equivalent thanks to this site. I have been curious as to how Frontline is able to charge so exorbitantly for its product; is it the real cost of raw ingredients, or simply an unexpired patent and no competition? Based on your link, it appears to be the latter. Any thoughts? Again, thank you.

  32. CB says

    I wish I would have done my research before buying the Kirkland brand for our dog and cats. I have used Frontline, with great results, but it is expensive. I have always thought highly of Costco brands, so I thought this would be a great way to save money. Now I’m kicking myself! All of our pets are itching, and on closer investigation, I can see that our dog now has fleas! Even when applied as directed, it spread all over our cats’ necks, shoulders, and backs, They tried grooming themselves, which they’re not supposed to do, got it in their mouths, and looked miserable. Needless to say, this product is going back to Costco.

  33. AB says

    My poor cat is itchy, greasy, and irritated after I put this on him. I’ve attempted to wash it off after reading this. It’s funny how Costco does not sell this product on their website therefore we are not able to post reviews. I appreciate this article and sharing about generics.

  34. Keaton says

    Wow. I am glad I found this site. My wife called from Costco to ask if she should buy the Kirkland brand, so I found this page and I’m glad I did. If these results are true I am really surprised they still sell this stuff. It’s been over a year since the first review on this page and it’s still on the shelves. If they sold something that did that to kids they would pull it in no time flat. They must have bought a boat load of it from China and they’re trying to make their money back! -_o Even though this is a Advantix page I don’t think this is a slam piece. This page made me look at some other review pages and they had similar results. Not gonna risk my pets’ health to save a few $.

  35. Cass Shepherd says

    Thanks for the review and the research. I have held off using this product until I knew more about it. I do think it is unfair of you to say that Costco is just trying to make a quick buck on the new generic Bio Spot product under the Kirkland name. Costco does and is known for standing behind their products and guaranteeing satisfaction or your money back without a hassle.

  36. Stanley Thal says

    I used the Kirkland Flea and Tick Drops for both my 14 year old and 4 year old Schiperkes. both got convulsions and seizures. he younger one survived the old one did not. Costco did not send recall notices about the prodct, they just removed it from their shelves and website. They have the means of sending recall notices to their customers but chose not do. Pets are sependible. I think Costco as a coporate citizen is reprehensible and dispicable. i am sueing them. i hoep everyone who has lost a pet due to their poor quality control soes the same.

  37. Norma says

    I purchased this product this morning for my cats. I put it on one first and her mood changed immediately. She hid under the bed and when my boyfriend went to check on her she scratched his hands several times. My cat NEVER scratches us, not even when bathed. We kept an eye on her and she still looked uncomfortable. She was breathing heavily and wouldn’t let us get to close. When she did let me pet her, she growled when I got closed to the area I put the product on. Not long after she threw up. I found this article and immediately bathed her. I have never seen her this upset or in pain. I’m upset I chose to buy this because I trusted the Kirkland brand. I’m going to keep an eye on her and hope she doesn’t get sick. She had the product on no more than 45mins. My cats have used Advantage in the past with no problems.

    • George Branson says

      Hi Norma,

      Sorry to hear about your cat’s reaction. Fortunately, most animals will fully recover from this type of reaction. You’ve done the right thing so far. Now you just need to keep an eye on her and she should get better progressively within the next couple of days. Hopefully sooner since you took fast action to get the stuff off her.

  38. Melinda says

    Just purchased the Kirkland product, am very hesitant to try on my dog and cat so I read everyone’s reviews. I have a medical background so I know what generic vs brand is all about. The doses in generic meds are uncontrolled, so each dose does not have the same dose of meds as every single other dose in that package. My best guess is the dogs that experienced side effects may have received higher than prescribed doses with each administration. This is a guess but it remains a possiblity. Less quality control means cheaper product, this is why brand name meds seem to work better.(this goes for human meds aswell). Now I will have to make vet appts. for my pets and get my money back from Costco.

  39. marylou says

    Two six-month old Basset Hound puppies. I’ve used Advantage on all my pets, up until this morning when I found the Kirkland brand and thought I’d give it a try. Seems like whenever I take the pups to a dog park, they come home with fleas. It’s been 6 hours since the application, and so far no ill-effects other than the “grease” spot. I’ll watch them closely, though. And likely will return the remainder of the product. Advantage II on its way from Drs. Foster & Smith, but I didn’t want to pups to have to wait until it arrives. SO….hoping I haven’t made a serious mistake. Pups will be spayed next week, so will be given the Capstar tablet then.

    • George Branson says

      Hi Marylou, I hope it works out for you. Just because some people have had bad experiences does not mean everyone will. Let us know how it goes! :)

  40. eric says

    I too was duped. Taking my dog to the vet today. He’s been pulling his hair out of his rear leg and creating a hot spot. I’ve bathed him and put “the cone ” on his head. Taking the remaining vials back to Costco. Very upset with this product. Should have stuck with the Frontlne plus. Price is not everything. Too good to be true is just that.

    I’m a pretty big costco fan, but this is a terrible product.

  41. SANDRA says

    Costco in Puyallup, Washington has pulled them off the shelf. my old Engllish Sheep is in Serious condition from this Kirkland flea & Tick.

    • vranhth says

      So this is A YEAR AGO.. Kirklan brand cat flea and tick was pulleed off the shelves .. My cat was seriously affected by the greasy burning product. I cannot believe it… I just bought mine at Coleman Costco, San Jose.. Oct. 2013..!!!!!!!!!!!!!!!!!!!!!!!! I’m shocked that it was still on the shelves in San Jose in 2013

      • CAROL SMEAD says

        It is still being sold at the Costco warehouses in San Joaquin County now and it’s on sell for $5.00 off making it a more tempting product to buy when you’re on a budget. This needs to be taken off immediately before more people lose their 4-legged children <3

  42. Theresa R says

    My cat is at the vet right now from putting this on her this afternoon. She was able to lick and ingest some of it I believe. She started panting very hard and her heart rate is up with fever of 103.8. The Vet has kept her to give her steroids and some benadryl to begin with. I’m very worried about her and feel absolutely horrible but I’m praying that because I got her in to the vet so soon that she will recover.. She was also twitching and just acting really strange. This has had a very nnegative effect on her.

  43. Shawna says

    Let me first tell you I work at a veterinary hospital. I know that the price is very tempting considering the price of flea control today. There is a reason your vet is recommending name brand products like Frontline and Advantage. They have the safety and research to back their products it is not about the money. We have been inundated with sick and or dying cats because of this product. People are spending hundreds of dollars on vet bills because they wanted to save on their flea products. We are currently reporting every case that we treat and are hoping others are doing the same to get this product pulled as too dangerous.

  44. Nancy Kawasaki says

    Thank you all for your reviews. I decided to try the Kirkland brand because I also thought they were comparing it to Frontline which has previously worked on my dogs. The price was also much better. Now after 2 applications my dogs are not better, in fact they are worse and have many of the same symptoms such as itching, lethargy, and anxiety. I decided to Google results and product reviews to see if others were experiencing the same results. I will be returning this product also and getting the Frontline again.

    • Leah says

      Total waste of money. I have used it for two months now and if anything, the fleas are getting worse. Totally ineffective. My poor Westie is scratching like crazy. Have purchased some natural flea sprays to try and keep the fleas at bay until the month is up and I can go back to using a reputable product. Costco should not be selling this stuff.

  45. Patti Tubbs says

    Please do not buy Bio Spot or Kirklands Flea and TIck medicine…. Both of my dogs got burns on their backs from this product. My 6 month old dog even has permenent hair follicle damage. How in the world they can sell it is beyond me….

    • Mary says

      Patti..I agree I see these posts go back sometime..and to know I was not aware and trusted Coscto product , figured at worst it wouldnt work..NOT THIS My poor Lexie is sooo sick and taking her to vet, HOW CAN THEY SHELF THIS???

  46. Dixie Dog says

    I believe this to be a B-S story just to knock a Kirkland (aka Costco) product. Although I did discover in this article that Bio-Spot and Kirkland Flea and Tick were one in the same. I’ve previously used Bio-Spot off and on over the previous 10 years on my boxers. I’ve had very good results with the product with no complaints. I also have used Frontline with very good results. Comparing 6 vials of Kirkland brand that is cheaper than 3 vials of Frontline, I will be using Kirkland from now on. Costco’s Kirkland brands are a premium product at a discounted price.

    • George Branson says


      These are real comments from real people. No BS here. You are the first person to post positive results. If it works for you, then that’s great.

    • Mary says

      Glad you didnt have any problem (by sheer luck) but DO NOT say this is B.S.! “Dixie Dog..” because YOU didnt have a problem thank God, does NOT mean we ALL have!! I have been up all night with poison control and a VERY sick little kitty..

    • vranhth says

      I have never responded to blogs until now.. The kirklland brand for cats has frightening side affects. First of all the amount of medication was suspect. 10 times more than Advantage. The Kirkland brand was greasy–very greasy and after 3 days of my cat hiding, I put her in the bath to wash the product off. She was laying on her side and lethargic-hiding all day and not moving. worried since I hear about recalls of dogfood etc coming in from china.. IS THERE anyone testing these prodducts?

    • CAROL SMEAD says

      Kirkland’s brand of flea treatment does not work and we have a vet bill for over $1000.00 to prove it. Our Chihuahua Maxie nearly died from her treatment. She weighs in at 5.8 lbs and since being in the hospital she now weighs 4.4 lbs. She was hemorrhaging, internally and we discovered this just 2 days after administering the Kirkland’s Brand. Never, ever again, moreover we are infested with fleas and cannot get this under control whatsoever. We have 13 days to go in order to treat with Frontline plus on the rest of our pets, cats and dogs. I feel sorry for our birds which are now scratching like crazy just as I am from the flea infestation our home is experiencing :((

  47. Jennifer Schanz says

    Got the same results as Nancy. Do not waste you money on this product. Now my poor Chihuahua is covered with fleas because I used this product last month and noticed her scratching alot and realized she was due for another dose and applied it. The next day I noticed she was still scratching and examined her and that’s when I finally realized this product doesn’t work at all. I now have to wait an entire month to put frontline on her in fear it would harm her if I did it now. Thanks alot Costco!!!!!!!
    This product should be taken off the shelf immediately!!!!

  48. gitte says

    Thanks for letting us know about this product. I’m not going to use it on my dog and I’ll return it ASAP!

  49. arlene johnson says

    The reason I found this discussion is because we put Kirkland Flea & Tick on our dog two days ago. And she has been lethargic-hardly moving at all –has occasional shaking movements-won’t eat–just is not herself-not well. And this happened within 30 minutes after applying Kirkland. We have always used Frontline Plus in the past without any negative side effects. And I believe the ‘demostation table’ at Costco’s was actually ‘comparing’ the Kirkland brand with ‘Frontline Plus’…or I never would have considered buying it. There was no mention of “Bio-spot’. !! I am actually going back there now to verify this. It is probably correct that you get what you pay for–but I was under the impression that I was receiving the actual “generic” brand of Frontline Plus–just as you see now in Walmart and Walgreens–with the same ingredients–and of course with much more ‘savings’ in quanity-cuz that’s what Costco does with other products. This product is being sold with deception information. I was a fool to trust Costco. Our dog is only three years old– very healthy & active doberman–not an old dog-

    • George Branson says

      I’m really sorry to hear about your dog. Hopefully, the effects will wear off soon. I agree that Costco has been somewhat deceptive by placing the Kirkland right next to Frontline. It makes people believe it is the generic version, and it’s just not even close.

  50. Rachel says

    The cat version made both of my cats horribly ill. They were weak, vomity, constipated, they couldn’t eat or drink. AFter a vet visit they were saved. I also had two friends of the family use it. One had a similar experience with all of their cats getting sick. Another had a rough burn on the back of her cats, they were ill as well. From the reviews I’ve read, we were lucky, some animals (dogs and cats) die from it. Do not use this product.

    • Nicole says

      Thank you for sharing this information. I used this product for the first time on both my boy cats. The results were that both cats became very tired, ate little, drank a lot of water and have thrown up water even though it has been a few days now. No difference noticed with flees. Both cats still very tired and staying very close to me. One, has lost hand fulls of hair even though there appears to be no noticeable burn marks on his skin.
      It had been a while since I had used a product like this so I carefully read the directions and followed them. Unlike products I have used in the past, this product did not absorb into the skin therefore causing a greesy layer which spread down the shoulders of the cats body making it easy for them to reach when grooming.
      I would not recommend putting this product on your animal.

  51. ET says

    This product did not work to prevent fleas and actually harmed my dog. The side effects were horrible (joint pain, loss of appetite, lethargy) and we will be returning it as soon as possible. Hugely disappointed that this was presented as an effective product by Costco.

  52. Sherree says

    I’m very disappointed in the Kirkland product. I will be returning it and purchasing Advantage Plus.

  53. Linda says

    So glad to have found this site. I am a Canadian and my sister lives in British Columbia and goes across the border into Washington State quite frequently. She was looking for K9 Advantix for me as we cannot get it here on the East Coast. She came across this Kirkland brand and bought it. I received the product a few weeks ago but was afraid to use it. I ended up purchasing K9 Advantix 100 from a local vet and was told we cannot get the K9 Advantix II in Canada. Anyway, my dog was having a terrible time with ticks and after having him groomed I applied the Advantix 100 and up until Saturday I have not seen a tick or flea. That was almost 4 weeks. My vet told me to reapply after 3 weeks because the ticks are so bad here. Funny though, he wandered off on me Friday and got in a bog and was covered in black mud. What a mess and what a stink. I had to take him to a dog wash. Since I was coming close to the end of the month I figured by washing him I finished off the last effect that medication would have. So out came the Advantix again and now there are no signs of anything at all. I am quite happy with this product and think I am going to give Kirkland brand a pass. I am sorry for my sister that she wasted her money. The cost of the topical and the postage was almost $40.00.

  54. Louise says

    I bought the Kirkland Brand, and see plenty of fleas 30 days later. This Kirkland product is inferior. It’s too bad. Most all Kirkland Brands are good.

  55. Rick says

    I used Kirkland flea and tick on my 20 lb dog because we were away on vacation and forgot and left the frontline home. My dog had picked up a lot of fleas and the campground we were visiting. The kirkland did not work as promised, actually I think the fleas got worse. When we returned from vacation I call my vet to see if it would be ok to do another flea treatment with frontline, he said NO that he had a pill that would work and it did. I also notice a lot of redness and irritation to my dog skin and he is scratching constantly. I had him bathed and he is still scratching. I never notice this problem before using Kirkland.

    • George says

      Greasiness and skin irritation also seems to be a common side effect people are reporting. Good move by not using Frontline or any other topical treatment while your dog’s skin was irritated, it could have gotten worse.

  56. Jay says

    I used the Kirkland cat flea treatment on my healthy 2 yr old cat. The product burned off her hair and burned holes in her skin. She went into respiratory arrest and was only saved by an emergency vet who gave her a steroid injection. My vet spoke to the hotline on the back of the box and was told that 1/2 their calls that day were for severe burns due to the product. The problem is not the chemicals listed but the ones not listed in the oil. My advice is avoid the horrible product and save your cat. If it is on your pet wash it off with dawn. If there are skin problems put vitamin e on it.

    • George says

      Thanks for sharing your experience. Just as I suspected, I’m afraid we’re just going to be hearing more horror stories as more people use the Kirkland flea product… I am very glad to hear that you got your cat to the vet in time and I hope he/she makes a full recovery.

  57. Nancy Weaver says

    So far I am not very impressed with Costco’s Flea and Tick control for dogs, as well as for cats. You would have thought I won the lottery with how excited I was to find an inexpensive flea and tic solution for my animals!
    I applied the medication as specified on the package, just like any other flea and tic control drops. Now, I have 2 VERY greasy cats and a Very greasy dog! Upon inspection, I see no fewer fleas then I started with 24 hrs ago!
    Not only am I disappointed and will be returning both products, I have to wait another month to re-apply…for fear of injuring or harming my animals with chemicals. In the mean time I have to watch my pets suffer with fleas! I will be giving all 3 of them a bath to remove the greasy residue so I can pet them and allow my children to play with them.
    Please heed my warning and don’t waste your time and money on this worthless product.

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