Alison and Tim Hysom joined Detective Inspector John Delaney at Ilford police station to appeal for the public's help in finding their 15-year-old daughter.
DI Delaney added: "We are taking this matter seriously and a lot of resources, including search teams, have been deployed. We are concerned for her welfare because she is vulnerable, she is suffering from depression and she is just 15.
"It is out of character and there has been no contact from her since the day she went missing."
More top news
The one-year-old Yorkshire Terrier was attacked and killed while being taken for a walk.
The lifeboat crew carried the pair into their boat and dropped them off back at Tower Bridge as people watched from the riverside.
The huge painting took two graffiti artists thousands of hours to complete in east London.