Is Boric Acid & Borax Toxic to Cats and Dogs?

"Natural" and "non-toxic" are not the same thing. Borax (sodium borate) and boric acid are low-toxicity compared to most insecticides, but they are mildly caustic and can cause vomiting, diarrhea, and mouth irritation — and large ingestions affect the kidneys and nervous system. A dog that licks a trace of powder will be fine; a dog that eats open bait powder by the spoonful needs a vet call.

The liquid or gel inside most commercial bait stations is heavily diluted — a single station eaten by a dog usually causes, at most, drooling and mild stomach upset, and the plastic shell is often the bigger (obstruction) concern. Multiple stations, or the raw powder form, are more serious. Count what was chewed and call with the product name; keep stations under appliances where paws cannot flip them.

Use it as a thin dusting deep in cracks, under appliances, and inside wall voids — places tongues and paws cannot reach — rather than visible piles along baseboards. Keep pets out of the room while applying, wipe up visible powder, and never mix it into bait blobs on open floors. Stored powder belongs in a sealed container up high; the fine powder is also an inhalation irritant for you.