Go Ad-Free
logoThe People's Perspective on Medicine

Will Borax Kill Cats As Well As Fleas?

Q. I’d like to relate my experience with 20 Mule Team Borax, which my vet suggested after I had problems with pesticides. He said I’d drop dead if I kept using flea sprays, as I’m extra sensitive to such things.

My indoor kitten came from the pound absolutely loaded with fleas. I put Borax on the carpet and carefully vacuumed it up. It worked beautifully and I haven’t had to do the Borax treatment again. I very rarely find a flea on my cat even though outdoor cats come near her on the screen porch. The powder did not make her sick, nor did it make my bronchitis flare up, so I’m sold on 20 Mule Team Borax.

A. Thanks for your story. We have heard from many readers who wanted to know whether Borax was really toxic to cats, as they read in our column. To say we are confused would be putting it mildly. Borax is sodium borate, which is not the same as boric acid. Boric acid is used as a pesticide, while borax is not. (This is not meant to dispute your report that 20-Mule Team Borax got rid of your kitten’s fleas.)

Boric acid can be used for flea control but it should only be used in areas that cats or small children will not come into direct contact with it. Here is a story from another reader of our newspaper column:

“I just finished reading your column about using borax for flea control. Let me tell you what happened with our cat. Our 15-year-old Siamese started having seizures. Tests revealed a tumor in the brain. Surgery was successful and she is now doing well.

“When the tissue was sent for analysis at the pathology lab they had trouble figuring out the exact components of the specimen. Further study revealed it was a granulomatous tumor caused by inhaling boric acid.

“We had used a well-known commercial product on our carpet to control fleas. Needless to say, we will never use boric acid again.”

Another reader recommended spreading borax on the carpet and carefully vacuuming it up. The residue was supposed to solve a flea problem. Regular, even daily, vacuuming (with or without borax) can be an excellent way to get rid of fleas. The vacuum cleaner bag should be removed from the house immediately after each cleaning so that the fleas do not escape. Diatomaceaous earth can also be used for flea control, but it too should be applied where the cat cannot get to it and breathe it in. A veterinary pharmacist has told us that any powder can be a problem if a cat inhales it regularly. Some exterminators use sodium polyborate, which probably should not be applied where the cat can be in direct contact with it.

After all this, the bottom line seems to be that you should always check with your vet to determine the safest flea control method for your pet!

Rate this article
star-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-empty
4.1- 98 ratings
About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
Tired of the ads on our website?

Now you can browse our website completely ad-free for just $5 / month. Stay up to date on breaking health news and support our work without the distraction of advertisements.

Browse our website ad-free
Join over 150,000 Subscribers at The People's Pharmacy

We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.