In the print ad, Grey poses nude in a bed and declares that "Too much sex can be a bad thing," referring to dogs and cats.
PETA, or the People for the Ethical Treatment of Animals, has been using scores of celebrities to help promote spaying and neutering in the U.S.
Grey, who plans announcing the ad campaign at a press conference on Friday at the Sands Expo Center in Las Vegas, said she believes in PETA’s initiative because about 8 million dogs and cats are dumped at U.S. animal shelters, and about half of them must be euthanized because of a lack of suitable homes.
"I think spaying and neutering is incredibly important," Grey said. "[I]t keeps the animals out of the shelters and there's too many unwanted animals out there already."
Grey’s PETA ad campaign was shot by celebrity photographer Andrew Southam.