« The Boy-Wonder Equine Surgeon | Main | Cat Bathing does not have to be difficult. »

February 17, 2007


Feed You can follow this conversation by subscribing to the comment feed for this post.


What type of shampoo can I use on small dog using frontline? She is itching constantly!!! Can I simply bathe w/water and dishsoap, something that doesn't have flea chemicals?


Hello, Robin,

Dishwashing soap will probably be very drying to the skin. Dog and cat skin has a lot different pH balance and is much thinner and more delicate than human skin. We occasionally use Dawn for de-greasing animals that have become contaminated with motor oil or machinery grease, but I wouldn't use it for routine bathing.

I would recommend a soap-free hypoallergenic pet shampoo, like HyLyt EFA. Your veterinarian should be able to help you with this.

Thanks for reading and writing.


Hi, love your site, have been reading through the archives after finding you via a Google search.

We just started our two (inside-only) cats on Advantage, as in they received the first dose this morning. Should we be okay with this? We put it on the base of their skull where they can't reach it (though it didn't stop them from trying!), so they can't lick it off. And like I said, they never go outside and we do not bathe them. Should the Advantage last all month?

Thanks for any info you can provide. Once again, love your site!


Hello, Sarah,

I think you will be happy with the Advantage on your house-cats. It is a good product, but it can't stand much bathing. Since most house-cats don't get much bathing, this should be no problem.

For my patients that go in and out, I really like Revolution because it also gives me heartworm prevention and protection from ear mites (which require direct contact to catch, so no problem with your house-cats).

Thanks for reading and writing.



Advantage nearly killed my cat. Three days after treatment (his behavior got worse and worse starting from the first day of treatment) he was listless and lying on the floor, unwilling to get up, shaking/seizures, unable to eat or even drink. I thought he would die that night - and stayed up with him all night - and took him to the vet first thing in the morning.

He had to be hospitalized and fluids given intravenously... and the first thing the vet asked was "Has he been poisoned?"

No, he wasn't poisoned by anything other than the Advantage - as it started the night I put it on him.

I would not recommend this product to ANY ONE who loves their animal - especially not for cats!


Oh - one thing I forgot to mention:

I even ran into a VET who, when I quizzed her about the effects of this poison (Advantage) said she would personally NEVER recommend Advantage to any animal.

That was the only vet I talked to who knew the scoop on just how many pets had died or were sickened by this horrible product.

It also "ate" a hole in my cat's neck where I put the original application of the product - and the hole refused to heal for weeks... bleeding and weeping - as if it had literally burned into his skin (which it had).

I will never use another commercial flea product again (whether it's vet-recommended or not). Some vets out there do know (and tell) the truth. They are rare, though. Most of them seem to care more about their sales of the product than the life of your animal, sadly.

I truly hope no one else's pet has to go through such a horrific experience - as it nearly killed my cat and broke my heart to see him like that.

As for Dawn: it may cause dryness, I don't know, or flakiness of the skin. But after that incident we did use Dawn and it killed every single flea and my cat was still healthy. It won't, however kill flea eggs. And the cat most likely won't like a bath. But it's better than having a sick animal. (Dawn will not sicken your animal; it is used on wildlife to clean their skin/feathers/fur etc. of oil after oil spills and has helped save many, many animals. Including mine - because I used it to wash off the Advantage (it is the only product recommended to remove Advantage).


Hello, Alexis,

I am sorry that you have had such a terrible experience. This is the first time I have heard of such a thing with Advantage, and I know that many people use it with no apparent problems.

Even when such an occurrence is rare, that is no consolation when it is YOUR beloved pet.

I suspect that you and your veterinarian have reported this adverse event to the manufacturer. If not, you should.

Thanks for reading and writing.


Thank you for responding - I appreciate it.

Well, we used Advantage on this particular cat three times. The first time, all he did was seem a little "off" - the second time, we noticed he was lethargic but not enough to warrant a vet visit. On the third time, he literally almost died from the product - which we couldn't understand because we only used it about once every year and didn't have problems before (other than a little odd behavior and lethargy).

Also, the dose we gave him on that last time was a SMALLER dose than we usually gave.

I don't understand why it happened but I know I can't trust it anymore.

I do thank you for your concern for my cat. You're right, it really is no consolation when it's a pet that you love.

I would love to trust Advantage again, but due to that last experience and the fact that my cat is very much loved, I just can't.

Thank you for responding to me ... have a good evening.



My dog swims a LOT. In the pond and in the pool. Will that remove advantage the same as a bath will? I know you said rain wouldn't have any effect.


Front Line Plus

@Marceia If he goes under water it is a possibility.

Jennifer Nichols

My cat nearly died from Advantage also. Our experience was almost exactly the same as Alexis'. I had used the product several times previously (more than 3 times) and it got worse each time until she had to spend several days in the vet hospital and get hydration treatments.

Another similarity that I'm noticing, that I've been wondering about, is that we both used product that was probably at least a few years old. Well, I know I did, and I assume if Alexis only applied once a year that she bought at least 3 applications which would make the last one 3 years old. I wonder if the chemical breaks down and becomes more toxic with time...


I will have to remember to check with the manufacturer on this. Most drugs are stable and effective long beyond their "expiration date". The date simply reflects the length of time the manufacturer has proven it will last.

Even when they are losing potency with age, there are apparently very few that then change into something toxic. No doubt there are instances of this, but it doesn't seem to be much of a problem. People would be dying like flies,as most hardly ever throw out old medicines. They "save a little in case I get it again later".


Can I use dog frontline on my cat if I use the correct dosage?


The only Frontline product that I am presently using is the spray. The spray is dosed in pumps per pound, regardless of cat or dog.

For the topspot, we had too many complaints about the product not giving full effectiveness for a full month. People asked if they could use a bigger size, use it more often, etc.

For dogs, we are now using Vectra 3D. With cat patients that we are seeing, we recommend Revolution. For over-the-counter sales, plain Vectra (no permethrin for ticks) made for cats.

My recollection on the Frontline is that Merial says that they are formulated in different concentrations. They did not recommend giving the dog product to cats when last I checked, but my recollection may be faulty.

If you call Merial they will certainly tell you not to.

Cats and dogs absorb things differently sometimes and it would be safest to stay with the cat product.


I have two cats who get flea treatments each month. Advantage works well on one cat, however for the other it caused complete hair loss and skin irritation at the application site (back on the neck). The fur did regrow slowly and the irritation healed. I can now only use Revolution sucessfully on the sensitive cat.


Hello, Cora,

Thanks for sharing your experience. There is no product that works for everyone.

The insert on Revolution notes that there may be hair loss at the site of application as a routine thing. We see it every once in a while.

Revolution is a go-to product for us, we really like it, but nothing is perfect for everybody.

Thanks for reading and writing.


We were told by the vet that Vectra would work for fleas on our small dogs, it didn't at all. Tried Frontline Plus, it helped but still seen 5-6 adults crawling and biting everyday-reduced the # of fleas, but didnt get rid of them. Then we finally found success when using Advantage II. The fleas are all gone, and every now and then she will bring in a hitchhiker and it will die within a few minutes of being on her. Advantage II is the best!!!!


Hello, Beth,

We have had very good results with Vectra 3-D. The Advantage II is very similar in active tick ingredient.

I am glad that you are having good results.

Did you treat the home and yard initially? If not, it doesn't matter what you use, you would keep seeing fleas.

John Doe

There's actually two very similarly named, similar products: Advantage and Advantix II. Advantage is fine for cats, but Advantix is deadly. Don't mistake them!


That is why the product is labled K-9 Advantix II. For many people "K-9" makes them think of dogs, as it should. The labeling clearly states it is not to be used on cats, as they permethrin in it is deadly to them.

Alas, people do not always read the labels, nor follow directions.


advantage just killed my cat 2 nights ago. I am devastated. The vet told me it was from the advantage. They tried to wash it off but he was too sick. He had seizure after seizure, and could not walk. He was in a lot of pain and shaking and crying. He also lost his bowels in the car on the way to the ER. It was an awful way for him to go, poisoned to death, and it is my fault because I am the one who put the advantage on him.


Hello, Aaryn,

I am sorry for your loss. This is a very surprising case. Imidacloprid (the stuff in Advantage) generally just sits on the skin, and is not absorbed. It is generally considered a very safe product.

There are other products that contain tick-control, such as K-9 Advantix II, that are usually deadly to cats. They are labeled for dog-use only, though.

If your cat was just terribly sensitive to the ingredient in Advantage, this is an incredibly rare occurrence, and there is no way you could have predicted such an outcome. You certainly shouldn't feel guilty about making a bad choice.

There was no way to predict such a thing.


Hi love your website. I have one cat and one dog a small chihuahua. I'm not really a dog person, have always had several cats but inherited the dog when the previous owner died. Can I put Advantage for cats on the dog if I use the correct dosage. I understand they have it for dogs as well but right now I don't have the money to buy one. I was hoping this might work til I get money next month. Also I only have one dose so will this at least help for the time being if I split between the cat and dog. Really can't afford it at all but like always I rob Peter to pay Paul! 😜


Hello, Karren,

The imidocloprid active ingredient is pretty safe. By the time you split a dose between two animals, it may not be enough to be effective, though. It is unlikely to hurt them.It's always best to use according to label instructions.


Hi I just started using Advantage on my cat as I have noticed the presence of flea extract on some areas on his skin. Is it ok for me to use dawn to wash off the flea extract from just his leg area (as this is where it is very bad). Or will that ruin the effectiveness of Advantage working? I would not give him a total bath nor would I get his neck area wet. Any advice would be greatly appreciated :) Thanks


Hello, Charlene,

By "flea extract" I am guessing you mean what we often refer to as "flea dirt", which is flea poop. Fleas are blood-suckers, and they poop out digested blood, which looks like black grit, kind of like pepper. If you wet it down on a white paper towel, you will see it dissolve into a reddish brown or red.

Dawn is a great de-greaser. It's not a great flea-killer. It will definitely strip off the skin oils and the Advantage along with it.

You could just rinse with water and that would take less of the Advantage. You could also give a good bath with pet shampoo before you put Advantage on the next time.

You can also use a fine-tooth flea comb to remove that debris.

Lynn Clemons

Well, I know for a FACT I DID USE ADVANTAGE II on my cat. He says in a er for pets as I write this. He began seizing this morning uncontrollably. Lethargic as well. So Bayer, after a angry call to my vet who said it was safe to use a small dog on a small cat!!! Said they have no record of ANY side affects of siezera or tremors. I think that's a crock of crap, I read too many on line complaints showing that it does. So my Archie is fighting for his life, my kids cat may not ever come home and all my vet can say is I don't know WHY he had that reaction! Bull!!


Hello, Lynn,

If you used the Advantage II for cats, it contains imidocloprid (the flea killer), which is pretty much non-toxic to mammals, and pyriproxifen (sterilizes flea eggs, should they live long enough to bite the cat and lay eggs), which is also generally considered non-toxic.

Certainly there are individuals who cannot tolerate certain drugs or chemicals, even when the dose is correct (according to safety testing done before the drug is approved for marketing). There people who cannot take an aspirin, which is pretty harmless for most of us.

If the cat had no exposure to any other compounds, and this is purely a reaction to the application of the Advantage II, that would be a very rare thing. Millions of doses are sold and used without a problem.

This does not mean it is impossible that the product is what caused your cat's problem. There are what are called "idiosyncratic reactions", meaning that it is unique to that individual. For other individuals, the compound is okay. For this individual, other compounds are okay-- it's not an unhealthy animal.

These are uncommon, and they are unpredictable.

The most common scenario that I see producing what you describe is where a well-meaning owner makes a mistake and applies a dog-only product containing permethrin to the cat.

We are also seeing more seizures from toxicity from the new mouse poisons that contain bromethalin. These are very tough poisons that cause brain swelling and seizures, and there is no antidote.

I haven't seen any controlled studies about how many woozy mice the cat would have to eat to get poisoned without eating the baits directly themselves. There are case reports of barn cats who would be consuming large numbers of mice that apparently have gotten enough bromethalin to cause seizures.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Comments are moderated, and will not appear until the author has approved them.

Your Information

(Name and email address are required. Email address will not be displayed with the comment.)