Dog owners, beware: Rat poison left on the sidewalk in Cobble Hill has reportedly caused the deaths of two dogs—and more poison has been found on sidewalks in Prospect Heights—according to the owner of a large Brooklyn dog walking company, Mobile mutts.

The owner, Jen Gladysz, was first informed of the rat poison, and of the dogs’ deaths (neither of which were clients of her own) through an email thread from neighbors who discovered the poison on Butler Street between Hoyt and Smith. The authorities were informed and tests confirmed that the blue pellets were, indeed, rat poison. Since then, the EPA has cleaned it up. In Prospect Heights, the rat poison was found near Bergen and Carlton streets, according to another email that Gladysz just received.

Though it cannot be confirmed, Gladysz also says there are reports from neighbors that the poisoning seems to have been targeted–not actually toward rats or pigeons—but specifically toward dogs.

Rumors are rumors, but rat poison is deadly—and for that reason, Gladyz says it was important enough, whether or not the poison was targeted, for her to get the message out. So dog owners, be extra cautious! As Gladysz wisely says: “It’s important for people to be aware that this happens, and for people to be warned to not let your doggies eat stuff off the street.”