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Has anyone had a bad reaction to Cheristin flea meds? - Page 3

post #61 of 90

After a little more research, I realize ALL the drugs involved are macrocyclic lactones.  They fall into three groups


The first group is the avermectin group which includes the drug added to Advantage to make it Advantage Multi, which also kills worms and protects against heartworm.  The "multi" part of Advantage Multi has nothing to do with the fleas.  It is Moxidectin.  Revolution also contains a macrocyclic lactone, Selamectin, which is considered to be a 'semi-synthetic' avermectin. The semi-synthetic variants of the avermectin group were created to produce improvements in many features of the macrocyclic lactone family including: safety (e.g. Selamectin is not thought to cross the blood-brain barrier as easily, resulting in improved safety for mammals, in particular ivermectin-sensitive breeds like collies.)  Some dogs and even fewer cats have a genetic mutation that allows these drugs to pass through the blood-brain barrier and if that happens, they get neurological symptoms that are extremely alarming and can be life threatening. I had a cat who had a neurological reaction to the moxidectin in Advantage Multi. 


The second group of macrocyclic lactones is the milbemycins (the main ingredient in Interceptor and Sentinel).  In addition it is used in Trifexis, in combination with a drug from the third and most recent group of macrocyclic lactones, the Spinosyn group.   I suspect that the cats and dogs who have died when given  Comfortis, Trifexis, Assurity and now the new Cheristin have the same genetic mutation, one that allows the chemical to cross the blood brain barrier and thus work on the central nervous system of the host just as it does the insect. 

Edited by Red Top Rescue - 7/23/16 at 5:17pm
post #62 of 90

I rescued a Feral Mother and her kittens. I am trying to find a Rescue group to take two of the kittens and find them a good home. I left the door to their room open, but Mother decided to look for a male cat, try to escape, etc. and climbed up in the insulation behind the furnace. I don't know if she was in the duct work or running along it. She also tried to hide her kittens and herself up in my sofa. Somewhere I think she woke up some dormant Flea pupae or whatever is dormant. I saw the kittens had fleas and knew the Rescue would not take them. I put Cheristan on them and my other three cats. My oldest is at least 18 and hyperthyroid. I had put Cheristan on him twice before, but he had lost two lbs. since I put it on him the last time. I put Cheristan on the cats 7/21 and he was worse immediately, crouching down, and then vomited. I tried force feeding him twice but he was dead when I woke up this morning (7/23). I don't know if it is a drug interaction with the medicine they take for hyperthyroidism, or just because they have another condition, or if they are elderly (I did not see that precaution in the literature) and my cat had been on antibiotics for a high white count a few months ago. Cheristan does seem to work better and longer than Revolution or Advantage II, but I don't know if it is worth risking the lives of your cats. My cats got fleas back long before a month was up when I used Revolution and Advantage II. I was more worried about my 3 1/2 month old kitten that had ingested some when her favorite chew toy brushed against where it was on her brother and she had bit into it and made quite a face. She also took a lick of where it was on her and made quite a face and staggered a little. Hard to put it where they can't get at it, when they are squirming. She seems to be okay.

post #63 of 90

I am really sorry your old cat died after you last used Cheristin on him.  The fact that he had lot two pounds since the last time you put it on him is very disturbing, since that's about two pounds in two months, which is a very extreme weight loss for a cat.  He was definitely sick, and whether it was related to the last two doses of Cheristin or not, there is no way to tell.   I can't tell you if it was a reaction to the methimazole you were using on him for hyperthyroid either.  I did look up drug interactions with methimazole on the human medicine site,tapazole.html and found that 67 drugs are known to interact with it.


My personal recommendation is that you do not use Cheristin on ANY of your cats.  Even though many have no problem with it, there are cats who are sensitive to the drug used in Cheristin and have died without the presence of any other drug.  We had a case just recently where three cats in the vet's office were given Cheristin.  Two were fine and one died. 


Advantage may not last 4 weeks, but it is very safe, has been used for years without any major problems, and it can be used as often as once a week for severe flea infestations.  You can also use a flea comb and comb the kittens.  Have a bowl of water with a little dish soap in it nearby and push the fleas out of the comb into the water where they will sink and drown.  (Don't dip the comb in water, it makes it harder to get the fleas out.)  This is the only flea control we had when I was young and it required a little time and effort but it saved many kittens from dying of flea bite anemia. 

Edited by Red Top Rescue - 7/29/16 at 1:12pm
post #64 of 90
Actually it was one cat that died and one survived from the cheristin at the vet office. still doing a lot of investigating though.
post #65 of 90
My cat was down for two days, but my concern is that I am now having a reaction from petting the cat. I can't stop itching, and the site that itches keeps moving from my hands to legs, to feet, to stomach, back of knees, chest, etc. Benadryl does nothing. So severe I will probably have to see a doctor immediately. Anyone with similar reaction?
post #66 of 90
I have not had or heard about this reaction. Hopefully you can figure it out. Good luck!
post #67 of 90

I have been feeding a lost cat for a few weeks. I think she has fleas and would like to know the right ratio of flea med. for a 6 pound cat. She hasn't gained much in the last 3 weeks. Any info on deworming would much appreciated too. thanks

post #68 of 90
Best thing to do would be to bring her to a vet so they can give her a deworm shot and apply FDA approved flea medicine on her. They will weight her to make sure it is the correct dose for both.
post #69 of 90

I just started using Cherisitn 2 months ago and it has worked as promised. My vet gave it to me when my cat started having fleas even though he had stuff on him. What a nightmare that was but the Cheristin killed them all, I also sprayed the house with Nyguard from a site that I buy bug stuff from and than heavens, the fleas are gone. I live in Fl. where they are always present. My cat did not have any adverse reaction. This is all I will use in the future.

post #70 of 90

We have been using Cheristin for about 6 months and our cat gets lethargic for about  day and then has no other side effects.

We live in S. Florida and fleas are a big problem.  Cheristen works very well for us.

post #71 of 90

I also live in Florida and all the flea meds I had been using just stopped working.  My poor three boys where going crazy so I bought and applied this new product, Cheristin. With in a day there were no more fleas.  ALL dead.  My cats suffered no harm and are still flea free after two months!!!


I know other have had nightmares, but I was in my own nightmare watching my cats with fleas.


post #72 of 90

My cat has had no problems with Cheristin. I,too, live in South Florida and the flea stuff I had used stopped being effective. What a nightmare that was. So far,so good with Cheristin or Revolution. I do need to find a better price than what the vet charges,though. Does anyone have any suggestions?

post #73 of 90

Thanks to all who posted NOT to use that flea med Cheristin. Luckily I don't use this on My two cats. I have been using Advantage Multi for the past 3 or 4 years, and in my opinion this flea med works well on my cats. Also they don't suffer from any bad side effects. The most I see is a mild case of lethargy, but that only lasts an hour. But after that, they are up and running. As long as they do well with this flea medicine, I don't plan on changing. Also I haven't seen any fleas on my cats either. They don't associate with other cats, feral or otherwise, so they never come into contact with any other cats. It's true that fleas are everywhere, whether your cats are around other cats or not. Fleas are even in the grass. When I first started using flea medicine, the vet said that even in the winter cats can get fleas. I was surprised. eek.gifSo I give my cats flea medicine year round.


 That was sad about that poor cat who died because the owner had used Cheristin. But she didn't know what the side effects would do to her cat. Poor woman. I want my cats to live a long life, so I'm sticking with what works for my cats. :)


Thanks again for posting this Important article.


Hugs, hugs.gif


post #74 of 90

DO NOT USE Cheristin!!!!!!!   It does work very well on the  fleas  but at what cost .   I had given both my cats  1 20 yr old ragdoll and 2  5 yr old egyptian mew. The fleas were gone by the next day but  so were my cats appetites.  Took them  both to the vet and both diagnosed with unrepairable  kidney failure.  So now most likely  will have to put them  both  to sleep if a miracle  doesn't happen soon 

post #75 of 90

How long did you use the cheristin on your cats. I have not seen any adverse reaction in my 16yr.old. Kidney disease does not come on quickly but over time and with advanced age. I would like to know the duration of use,please..

post #76 of 90

What would you do if the regular flea meds quit working?  I watched my three boys get eaten alive using both front line and Advantage. 


I tried the Cheristin and it worked great.  I have now applied it to 6 additional cats at my office and all are doing well being without fleas.


I am not saying that some might have a reaction but it worked for me and that is all I can report

post #77 of 90

Hello,I found this site by Googleing Cheristin.Our precious orange kitty,Gina died after being treated with Cheristin for the first time.She also had vaccines (that she has had several times before with no re-actions) updated at same time.She went in for a senior check up( she was about 12 1/2 she was a rescue kitty-we had her 10 + years) and we was told she is in good health only ageing.The vets said she would be lethargic from vaccines so we didn't go looking for her when we didn't see her for a while.My daughter found hours later in a closet -she seemed to be in a paraylized state she seemed to be frozen but alive).It was after emergency hours for vets.Gina died around 7:30 am the vets open at 8:00 am.It was horrible.The vet suggested we use this new product Cheristin instead of the all natural Sentry products I had been using on her Of course the vet is so sorry our beloved pet passed away.

post #78 of 90
Originally Posted by threecatowner View Post

Vet just gave me this for cats, I've always used Frontline or Revolution (which I can only get by prescription).   Apparently there were so many complaints of Frontline no longer being effective, they switched to Cheristin.

I'm wondering if anyone here has experience with this med - I don't want to use if it's causing bad reactions.

I am watching my sweet girl, Baby, fighting effects of Cheristin. She was 12+ lbs a year ago, but is now 6 lbs. Emaciated.
Hair loss, weight loss, appetite loss, energy loss... She went through phase of severe itching, lost belly fur. Got better for a while, until we treated other two cats who'd had no bad reaction last year. Within a week, Baby was itching, losing hair again... Severe weight loss particularly in past 3 weeks. Vet thinks it could be thyroid problem, dismissed my concern that it was related to Cheristin.
Doing blood work to be sure, but am printing out everything I can about people who've experienced side effects. I would not use this on any cat again. BE VERY CAREFUL!
post #79 of 90
Advantage and Frontline had stopped working, so vet gave us Cheristin to use on our 3 cats, all aged about 12 years old.
Two had no problems.
One has had extreme reactions. Intense scratching, hair loss, weight loss. Vet doesn't believe it's caused by the Cheristin, but it was an immediate response to this single new medication. And the hair loss began at the application site.
She was a plump and very furry 12+ lb cat, and has never had a single health issue till now. Is now 6 lb, and has lost virtually all of her muscle tissue.
I am taking her to a different vet as soon as possible, but I am concerned it will be too late.
Can a cat recover body/muscle mass after such extreme change?
post #80 of 90
@ADoug Is so sorry to hear this about your kitty! Cats can recovered, but it sounds like your girl needs immediate intervention. She has lost half her body weight and is likely suffering from hepatic lipidosis (fatty liver disease), if not having other issues as well.

How long ago was the Cheristin applied? Over how many weeks has she lost the weight?

Has she had recent blood work including checking her thyroid level (T4/Free T4)?
post #81 of 90

@JaxTabby,what you can do if the safe topicals are not working on the fleas is (1) treat the environment (assuming they are inside) with DE (diotomaceous earth, the edible kind you can get at flea stores) and you can use it as a flea powder on the cats as well; and (2) daily flea combing and knocking live fleas out of the flea comb into slightly soapy water in a bowl (we call that making flea soup) may not have them 100% clear but will help them a lot.  Remember, unless the flea infestation is massive and the cats are kittens, fleas are unpleasant but not life threatening.  Some of these chemicals ARE life threatening to SOME animals.  Just like humans, some people are allergic to things that others are not, and allergies (like to peanuts) can be bad enough to kill you.  Cheristin has enough bad history that it is not something I would ever try on any cat.


@ADoug, your vet is very narrow minded.  After reading this thread, surely you can see that some cats have serious problems with this, and your vet should have considered this one cat may be allergic.  I think you should get her to another vet, preferably at an accredited animal hospital (AAHA, you can search them here:


It sounds like she needs immediate help and should have blood tests run to see if her kidneys and liver are functioning properly.  Hopefully it isn't too late to save her.

post #82 of 90
I can only testify from personal experience. I am not saying that cats are not being harmed.

Now my vet carries Cheristin and I mentioned the horror some are going though and she agrees with me that some cats are hyper sensitive, just like some humans.
post #83 of 90
Originally Posted by Jules10 View Post

I called up Elanco and told them my cat has died a horrific death and that I believe Cheristin for Cats is the culprit as it is a neurotoxin and her symptoms were neurologically based!  Running around in circles and unable to jump or move -- she was paralyzed, just like the fleas that Cheristin kills.  Throw in a batch of cats and bingo, you have not just dead fleas, but dead cats to go with the fleas!

 I also told them it made all of them lethargic and they denied knowing of this side-effect.  I told them that it says this ON THE BOX  ok?  They said it did not say it on the box!  I said it states in can cause "inactivity" which is a synonym for "lethargic".  Gotcha you liars!

They claimed it is not absorbed systemically.  If it is not absorbed systemically, then why does it last for 30++++ days?  Gotcha again you liars!

I have gotten rid of this crap!  As of now, my other cats do not have any fleas as they are being kept indoors and I continue to comb them daily to be sure they don't have any.

As for my cat that has died, I am still very depressed about this.  I cannot get over what happened to her!  It angers me the way Elanco lies!

Do not trust Elanco!  They had told me I had to use Cheristin on ALL of my cats for it to be effective for the one that died that has the FAD.  I asked about this again when I spoke with them and their story has now changed!  They said they recommend that "another product be used" and that I did not have to use the pricey Cheristin for Cats on all of them.  Having to specifically purchase Cheristin for Cats has been a financial hardship for me as I live on a pittance unfortunately! Do they care?  Hell no, they are in this for one thing and that is the $$$!  Gotcha again you GREEDY LIARS!

That is three lies right there.  How many more lies are there Elanco?

How many cats have died from this toxic poison?

My Pepper is having issues with her back legs. Took her to the neurologist to see what's up. While there I told him about issues that Cheristan may have and he said to call Elanco.

THEY TOLD ME THEY HAD NO RECORD OF COMPLAINTS ABOUT CATS WITH NERVE OR DAMAGE TO THEIR SPINE!!! Do you have any record as to when you called and who you talked to?
post #84 of 90
Originally Posted by BelleL View Post

My Pepper is having issues with her back legs. Took her to the neurologist to see what's up. While there I told him about issues that Cheristan may have and he said to call Elanco.

THEY TOLD ME THEY HAD NO RECORD OF COMPLAINTS ABOUT CATS WITH NERVE OR DAMAGE TO THEIR SPINE!!! Do you have any record as to when you called and who you talked to?


Originally Posted by BelleL View Post

My Pepper is having issues with her back legs. Took her to the neurologist to see what's up. While there I told him about issues that Cheristan may have and he said to call Elanco.

THEY TOLD ME THEY HAD NO RECORD OF COMPLAINTS ABOUT CATS WITH NERVE OR DAMAGE TO THEIR SPINE!!! Do you have any record as to when you called and who you talked to?

Jules10:  Sorry to hear about your loss.  Fortunately I don't use Cheristan.  Advantage II for

large cats is my product of choice.  Hope you get the feedback from others who are using


post #85 of 90
My vet sold me a six pack of Cheristin so I used it on my longhaired cat all last summer. She always reacted as if the topical application hurt her but I couldn't see any signs of skin irritation and the vet said to continue dosing her every month, which I did.

When I gave her the last dose last fall she cried and the next day the skin at the application site was red. That redness only lasted one day. The vet told me to stop it for the winter months but to start up again in the spring. I'm undecided about whether or not to buy another six pack. I'm terribly allergic to flea bites so I have to give her something but, even though the vet swears by Cheristin, I'm not sure that's the best thing for her.
post #86 of 90

I opened THREE CASES w/Elanco as all three of my cats were sickened by this poison.  They are liars ok?  See my extensive review under Cheristin for Cats on this site under reviews  I suggest you print out the link on there which identifies the ingredient as a toxic poison!  It is all right there under the name of this same product called ASSURITY that was pulled off the market due to deaths!  It was reintroduced as Cheristin for Cats in a weakened form.


Read my extensive post(s) on Cheristin for Cats here:


If you put this on your cat and it gets sick and dies, it  is on you because YOU WERE WARNED.


As for the person with the Siamese cat, this particular breed of cat is especially highly sensitive to the chemical that is in this crap.  Do not buy another 6-pack!!


I am using nothing now at all but a comb and a bit of butt busting work to keep fleas out of my home.  At present, I have had no fleas for well over a year by doing the work to keep the house clean and the cats flea free.  Do not allow them to go outside as that is where the fleas come from is my advice.




The vet that noted no sensation in her spine retired recently and I do not know where he now lives but I do have the records on my visit to his office that day and she was dead 2 weeks later due to NEUROTOXIC PARALYSIS!  Not a sweet way to go that is for sure!!

Edited by Jules10 - 2/28/17 at 9:25am
post #87 of 90

Don't do it!  Please do not do it! 


Spinetoram (XDE-175-J) - Identification, toxicity, use, water pollution potential, ecological toxicity and regulatory information


Click on this link above and READ what it says about ASSURITY, the weakened form of spinetoram and the fact that it is cancer causing (among other things!). 

post #88 of 90

If you call Elanco they will tell you they have never heard of a problem like this.  The vet I talked to was rude and condescending and as mentioned by RED  TOP RESCUE, it is a waste of time to call them.  You can do this any way to report the side-effect you are noticing as they will have to open a case # on it but they will do nothing!   Their phone number is:  1-888-545-5973.  Being it is not regulated by the FDA you are out of luck with them and they will not help you.   As for info., good luck because Elanco does what they are paid to do and that is LIE! 


Ask YOUR VET or the neuro IF they have HEARD about the Trifexis for dogs deaths.  If they have not, find another vet/neuro.  This is on Facebook under "Does Trifexis Kill Dogs?".   The chemical in Trifexis that DOES KILL DOGS is very similar to spinetoram and is called spinosad and is aka COMFORTIS tweaked with a heart worm component FYI.

post #89 of 90

IMO the drug companies will say anything to protect sales of their products. Certainly quite a lot of cats seem to tolerate Cheristin, but for how long remains to be established. I believe that the best place to break the fleas' life cycle is OFF THE CAT - by way of good housekeeping such as frequent vacuuming of furniture and bedding. This with the occasional use of Advantage has worked for me. I don't want my cats to face premature death for my convenience - quite a few of my cats have lived to 20.

post #90 of 90

I applied Cheristin to four cats to deal with fleas.

They all just hated the application, reacting as if I was hurting them.

They ran off and hid, and flinched from me if they thought I was heading for their necks.

They seemed a little out of sorts the following day, but nothing outrageous.

Then one of them, about two weeks later, started shedding a huge patch of skin from where I'd applied the Cheristin.

This is a thick layer that looks more like leather than a scab, a bit over an inch in diameter.

About half of it has detached and is hanging loose, while the rest is still connected.

I don't know what he'll be left with when it finally all peels off, whether he'll ever get fur back there.

But I do know this is not at all okay, and that I will not be applying this drug again.

I would not recommend anyone use this product on their cat.

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