Rosie O'Donnell Rosie O'Donnell

Rosie O'Donnell's 17-year-old daughter Chelsea has been missing for a week and may be in need of medical attention, O'Donnell announced Tuesday.

According to a Missing Persons ad that O'Donnell posted on her website, Chelsea was last seen on Tuesday, Aug. 11 in Nyack, N.Y., when she left home with her 6-month-old therapy dog, Bear, a 9-pound brown and black terrier. Police have been searching for her since Sunday.

"Chelsea stopped taking her medicine and is in need of medical attention," the ad reads.

O'Donnell posted pictures of Chelsea and Bear on Twitter Tuesday, adding that the pair may be in New York City.

Chelsea is O'Donnell's adopted daughter with her ex-wife, Kelli Carpenter.

Anyone with information is asked to call 911 or 845-358-0206.