Yes, you have to be very careful.

One of the cats in our household (some years ago) started to feel poorly, so we took her to the vet. There was nothing obviously wrong... but she was an indoor-outdoor cat and would like to wander around the neighborhood.

After spring turned to summer, she started to be her old self. The vet theorized that she would drink from puddles and streamlets downslope from people who were fertilizing their garden, and it was just enough poison to make her feel sick, but not really give her an infection or kidney problems. As summer cam and the dry season ended those drinking sources, she got well by herself.

But yes, you do have to be very careful.

=^..^=