Nini Stephanie JoJo

Are some flea medications toxic?

I used a Costco brand flea control on my cat. It is a Kirkland product. My cat vomited and had diarrhea two days later. Could the cause be the flea medication? I can not think of another cause. The cat is kept in the house. The medication itself was a large amount of oily fluid. I am throwing the rest away, but I do wonder if other cats have had problems with it?

Asked by Nini Stephanie JoJo on Jul 25th 2014 Tagged fleas, controlmedication, kirklandbrand in Health & Wellness
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Orion Hemingway

It is a definite possibility. Try another over the counter product next month. You might prefer to give capstar anti-flea pills after this experience. If she does not react well to that one either, schedule a vet visit to explain the problem. ^_^

Orion Hemingway answered on 7/26/14. Helpful? Yes/Helpful: No 0 Report this answer


If it causes the flea to DIE when the flea bites the cat, then it is a toxic substance. It is better to find something that repels the fleas so they do not want to get on your cat in the first place.

Groucho answered on 8/9/14. Helpful? Yes/Helpful: No 0 Report this answer


If you don't mind my asking, why does an indoor cat need flea medication? I would check with the vet if I were in your situation, to see if this medicine is even necessary.

Pippa answered on 10/12/14. Helpful? Yes/Helpful: No 0 Report this answer