by Marty Fisher, EMGV
We recently used glyphosate (an active ingredient in Roundup) on some vicious and pernicious weeds that were growing in the gravel pathways in our garden. Without thinking, I let our Siamese kitty, Elsa, out shortly afterwards. About an hour later, she was at the door, drooling, vomiting, teary eyed, and obviously very uncomfortable.
Not even thinking about the weed killer, I googled cat drool and found a number of possible causes, including pesticides and insecticides. So, I then googled glyphosate and cat drool, and low and behold, all of her symptoms were listed. I feel sure she walked through weeds that had been sprayed, and then licked her paws. I felt terrible!
The information I found online said to offer water, which I did, but she was not interested. She didn’t seem gravely ill, and the online information indicated it would likely resolve itself. After sleeping the rest of the day and night, she was fine the next day.
The label says it is safe for pets and children—but only after it dries completely. According to the National Pesticide Information Center, pets who come into contact with a wet herbicide may drool, have stomach upset, lose their appetite, or become sleepy.
Other chemicals used in mixtures with glyphosate can be the real problem. The label also listed the active ingredient diquat dibromide. According to a study conducted by the California Environmental Protection Agency Department of Pesticide Regulation, diquat dibromide causes cateracts in dogs and rats., and as the potential to cause cataracts in humans.
Diquat is added to some formulations of herbicide, really just to make consumers feel like they have accomplished something. Glyphosate itself can take a while to work, so it is often mixed with a kicker like diquat that has more immediate action. However, those faster pesticides tend to just burn the leaves, which looks good, but can actually hurt the efficacy of the glyphosate, which is the real heavy lifter. Chemicals like diquat can also have more harmful side effects because they are meant to cause chemical/physical damage more or less on contact, as opposed to being more systemic within plant like glyphosate.
Before you let your pets out after spraying a commercial weed killer, double-check to be sure the area is completely dry. And, as with all chemical pesticides and insecticides, use it judiciously and only as a last resort.
National Pesticide Information Center: http://npic.orst.edu/
California EPA study: https://www.cdpr.ca.gov/docs/risk/rcd/diquat.pdf
Read Marty’s previous and post about glyphosate here.