Cat sick after flea and worm treatment

Hi there, I wonder if anyone has experienced anything like this with their cats. Three days ago I used a spot on flea and worm treatment on my cat (Advocate by Bayer for cats under 4kg), and since then she's been very quiet, just sitting in her basket and barely eating. She's nine and otherwise in good health, but a bit overweight. Last winter she was sick and then disappeared for about a week and came back better. Our other cat got the same thing, which the vet said was pneumonia, but I think was actually some virus, and he died. But she's been fine since then. She lives outdoors with 3 dogs and four other cats, but I brought her inside now cos she's sick. She's neutered since she was 18 months. She's had one little of kittens. She's not vaccinated though, most people don't vaccinate cats in Ireland. She not getting sick or having diarhoeia and she's alert and walked around slowly a little, but then went back to her basket. She's seems in her normal mood (a little grumpy but friendly at the same time) but is definitely not herself. She's normally pretty active for her age. All my other, younger, cats and dogs were fine after the flea treatment. It doesn't seem like an emergency but does anyone know if it's sometimes normal for a cat to be a little sick after this? Or should I take her to the vet straight away? Thanks for any answers,

Oh yeah, and the cat probably had a few fleas before this, because they were all scratching a bit, and I saw a worm on one of the cat's tail, but she's this cat's enemy, so they don't go near each other, but yeah, she might have had worms too. Just in case this is important. Thanks.

Hi - I do know that some cats can have a reaction from these treatments. I put Revolution on my cat a few years back and he had a bad reaction where he started foaming at the mouth. It passed rather quickly and he was ok, but to be safe you should probably have her checked out by a vet.

One of my cats also foams at the mouth when he get his flea treatment. He gets himself real worked up about taking medicine. He did it once at the vets office too when he was given medicine and he said it just happens sometimes and he was fine a few minutes later. He is really old so that may have something to do with it.

Bayer has a web site and you can look up Advocate for cats. It has warnings listed but is vague on the reactions. Talking to the vet or taking her in would be the safest. It could be an unrelated health problem. Things like diabetes, cancer, etc. could cause similiar symptoms.

I have not seen a reaction like that with the Revolution, Frontline and Advantage products that I have used in the past.

I hope she is better soon.

Originally Posted by Skimble

I have not seen a reaction like that with the Revolution, Frontline and Advantage products that I have used in the past.

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The foaming at the mouth happens if one even slightly puts the flea treatment a little low - cats actually have a pretty good reach.

I've had a cat react to Advantage, very much like the OP's cat - lethargy and just not really wanting to eat. It did completely pass in two days, though.

(and before anyone asks or thinks differently, yes the Advantage came from my vet)


Call the vet, it certainly can't hurt to be cautious.