Bayer’s Advantage® II flea treatment for cats contains unlisted inert ingredients that may cause permanent neurological damage to your cat or dog (vetinfo).
Advantage® II for cats contains an active ingredient which acts on the nervous system of the flea. It is called: midacloprid, an insecticide. It is interesting to me that it attacks the flea’s nervous system.
This chimes with at least two comments that I have noticed on this product. One is on this website and the other on Amazon. Here are the comments:
The first couple of days after applying this product to my cats it seemed to be working great. Especially for my cat who seems to be very sensitive to fleas. However today I watched one of them fall off a fairly tall piece of furniture twice (something he is on every day and has never fallen off of before) and strangely like he went limp or something. Then a little while later I watched as my other cat who was just standing on the floor fell with her back legs slamming together and her front paws trying to get a grip. Then I read on a few different websites that it has been found that in RARE occasions this product can have neurological effects….(Amazon).
My 4 year old cat cocoa is an indoor cat but she gets out sometimes i recently changed her liter to all natural liter and gave her a dose of small cat advantage 2 which was dose number two of three but instead of every month i give her every couple months never noticed her being allergic to it but after letting her inside one day the day after i noticed she was hiding out on top of a bin i lifted her up and she waslimp for the next couple of days she wouldnt eat or get up when she did it took a lot of energy i noticed a line of fur missing no wound and nowher belly near her nipples is reddish brown i have an appt in a couple days but it is killing me not knowning please help…(this website).
Each cat caretaker needs to check this out themselves but it appears that the insecticide can also attack the nervous system of the cat. The vetinfo.com website states in reference to its use on dogs:
It can enter his circulatory system and cause brain damage and nerve damage.
That statement supports the comments of the two users quoted on this page. Although, the website states it is one of the safest treatments for fleas on dogs.
Now, as far as I am concerned if a potential, albeit rare, side effect is this serious, it is unusable. It is about risk but it is also about the upside and downside of using drugs like these and insecticides are dangerous chemicals.
The vetinfo website adds an important extra bit of information about this drug. They say some of the inert ingredients in the product are not tested for safety because they don’t have to be under the law. Also, even if these inert ingredients are toxic they don’t have to list them. I’ll quote the site verbatim for the punch line:
Such undisclosed ingredients might be unsafe for use on your pet and the neurological damage caused by them may be permanent.
Has anyone more knowledge about this flea treatment? When I see “neurological damage” and “permanent” in one sentence as a possible side effect it puts me off buying it. Does it do the same thing to you?
Used advantage 2 on my cat (trusted the vet). He has lost half of his fur and has severe neurological problems. He can barely walk or stand. Will this improve? It has been about 6 weeks now. If not I will probably have to put him down. There is no warning about this on the box. Are there any class action suits out there against Bayer? I’m mad as hell
Thanks for commenting. A vet will advise on recovery. I’d have thought your cat would recover at least substantially but I am speculating. I don’t believe there is a class action. There should be. Good luck to you both.
I used this on my cat yesterday and today he’s been showing neurological signs like twitching and jerking and his fur is also falling out. He seems to be unsteady in his gait and I’m so worried about him. I’ve never seen this reaction before as I’ve used it on my other cats with no problems. Is your kitty any better?? Why don’t they list this as a potential side effect??? I’m also mad as hell!
It can certainly cause neurological damage. One of my cats started having balance problems as a result. Luckily she’s been improving with time.
Otherwise healthy cat now has front paw muscle tremors when laying down and stretching out his arms, I know due to Advantage II application. Now I’m fearing that it’ll get worse. I’m never putting it on him again. Has anyone experienced the same, did it get better, did it get worse does it stay the same? Hes 4 yrs old. If a cat licks this he ingests it then it gets into his bloodstream and into a central nervous system. The cat’s central nervous system and an insect central nervous system is different but still it’s a pesticide anyway you cut it!!
Thanks for sharing Carolyn. So sad though. These flea treatments are potentially very dangerous.